NOIP前刷水行动

2016.11.15

BZOJ1009:DP+矩阵乘法+KMP

BZOJ1898:矩阵乘法

BZOJ4101:贪心，考虑我们往右边撞的时候，我们会向左边冲

　　　　　　，于是枚举答案点利用一个指针计算即可！

2016.11.14

OI队内测试

2016.11.13

BZOJ4512：乱搞

BZOJ4102：DP+bfs

BZOJ4395：bfs

BZOJ3889：双键值最短路

BZOJ4512

#include <bits/stdc++.h> 
using namespace std; 
#define LL long long 
int N,sx,sy,ans; 
char s[1020]; 
bool vis[2020][2020],north[2020][2020],east[2010][2010]; 
int main(){ 
//    freopen("data.in","r",stdin);
//    freopen("A.out","w",stdout);
    scanf("%d%s",&N,s); 
    sx=sy=1010; 
    for (int i=0;i<N;i++){ 
        vis[sx][sy]=1; 
        char ch=s[i]; 
        if (ch=='N'){ 
            sy++; 
            if (!north[sx][sy-1]&&vis[sx][sy])ans++; 
            north[sx][sy-1]=1; 
        } 
        if (ch=='S'){ 
            sy--; 
            if (!north[sx][sy]&&vis[sx][sy])ans++; 
            north[sx][sy]=1; 
        } 
        if (ch=='E'){ 
            sx++; 
            if (!east[sx-1][sy]&&vis[sx][sy])ans++; 
            east[sx-1][sy]=1; 
        } 
        if (ch=='W'){ 
            sx--; 
            if (!east[sx][sy]&&vis[sx][sy])ans++; 
            east[sx][sy]=1; 
        } 
    } 
    printf("%d\n",ans); 
}

BZOJ4102

#include<iostream>
#include<algorithm>
#include<cstring>
#include<cstdio>
#include<cmath>
#include<queue>
#define ll long long
#define ld long double
#define N 1005
#define M N*(N+1)
using namespace std;
int n,p,tot;
int pre[M],v[M],now[N],f[N],dis[N][N];
bool vis[N];
queue<int>q;
struct data{
    int val,pos;
}a[N];
int read()
{
    int x=0,f=1; char ch;
    while (ch=getchar(),ch<'0'||ch>'9') if (ch=='-') f=-1;
    while (x=x*10+ch-'0',ch=getchar(),ch>='0'&&ch<='9');
    return x*f;
}
void ins(int a,int b){++tot; pre[tot]=now[a]; now[a]=tot; v[tot]=b;
}
bool  cmp(data a,data b){return a.val<b.val;
}
void bfs(int u)
{
    memset(vis,0,sizeof(vis));
    q.push(u); dis[u][u]=0; vis[u]=1;
    while (!q.empty())
    {
        int x=q.front(); q.pop(); 
        for (int p=now[x]; p; p=pre[p])
        {
            int son=v[p]; 
            if (!vis[son])
            {
                dis[u][son]=dis[u][x]+1;
                q.push(son); vis[son]=1;
            }
        }
    }
}
int main()
{
    n=read(); p=read();
    for (int i=1; i<=n; i++)
    {
        int x=read(),d=read();
        a[i].val=x; a[i].pos=i; 
        for (int j=1; j<=d; j++) {int y=read(); ins(i,y); ins(y,i);}
    }
    for (int i=1; i<=n; i++) bfs(i);
    sort(a+1,a+n+1,cmp);
    for (int i=1; i<=n; i++) f[i]=a[i].val;
    for (int i=1; i<=n; i++)
        for (int j=1; j<=i-1; j++)
        {
            if (a[i].val>a[j].val && dis[a[i].pos][a[j].pos])
            {
                f[i]=max(f[i],f[j]-dis[a[i].pos][a[j].pos]*p+a[i].val);
            }
        }
    int ans=0;
    for (int i=1; i<=n; i++) ans=max(ans,f[i]);
    printf("%d\n",ans);
    return 0;
}


BZOJ4395


#include<iostream>
#include<algorithm>
#include<cstring>
#include<cstdio>
#include<cmath>
#include<queue>
#define ll long long
#define ld long double
#define N 205
#define M 40005
using namespace std;
int dx[4]={0,0,1,-1},dy[4]={1,-1,0,0};
int pre[M],v[M],now[N*N],tot;
int n,m,ans;
queue<int>q;
bool vis[N][N],lig[N][N];
int read()
{
    int x=0,f=1; char ch;
    while (ch=getchar(),ch<'0'||ch>'9') if (ch=='-') f=-1;
    while (x=x*10+ch-'0',ch=getchar(),ch>='0'&&ch<='9');
    return x*f;
}
int encode(int a,int b){return (a-1)*n+b;
}
void ins(int a,int b){
    ++tot; pre[tot]=now[a]; now[a]=tot; v[tot]=b;
}
int main()
{
    n=read(); m=read();
    for (int i=1; i<=m; i++)
    {
        int a=read(),b=read(),c=read(),d=read();
        ins(encode(a,b),encode(c,d));    
    }
    int last=1; ans=1;
    for (;;)
    {
        q.push(encode(1,1)); 
        memset(vis,0,sizeof(vis)); vis[1][1]=1; lig[1][1]=1;
        while (!q.empty())
        {
            int pp=q.front(),x,y; q.pop(); //last++;
            for (int p=now[pp]; p; p=pre[p])
            {
                int son=v[p]; x=(son-1)/n+1,y=(son-1)%n+1; 
                if (!lig[x][y]) lig[x][y]=1,ans++; 
            }
            x=(pp-1)/n+1,y=(pp-1)%n+1;
            for (int i=0; i<4; i++)
            {
                int xx=x+dx[i],yy=y+dy[i];
                if (xx<1 || xx>n || yy<1 || yy>n || !lig[xx][yy] || vis[xx][yy]) continue;
                vis[xx][yy]=1; q.push(encode(xx,yy));
            }
        }
        if (last==ans) break;
        last=ans;
    }
    printf("%d\n",ans);
    return 0;
}


BZOJ3889

#include<iostream>
#include<algorithm>
#include<cstring>
#include<cstdio>
#include<cmath>
#include<queue>
#define ll long long
#define ld long double
#define inf 100000000000000
#define N 1005
using namespace std;
int s,t,m,n;
ll a[N][N],b[N][N],dis[N],d[N];
int c[N];
bool vis[N];
queue<int>q;
int read()
{
    int x=0,f=1; char ch;
    while (ch=getchar(),ch<'0'||ch>'9') if (ch=='-') f=-1;
    while (x=x*10+ch-'0',ch=getchar(),ch>='0'&&ch<='9');
    return x*f;
}
void spfa()
{
    for (int i=1; i<=m; i++) dis[i]=inf;
    dis[s]=d[s]=0; vis[s]=1; q.push(s);
    while (!q.empty())
    {
        int x=q.front(); q.pop(); vis[x]=0;
        //cout<<"         "<<x<<endl;
        for (int i=1; i<=m; i++)
        {
        //    cout<<i<<" "<<dis[i]<<" "<<dis[x]<<" "<<a[x][i]<<endl;
            if (dis[i]>dis[x]+a[x][i] || ((dis[i]==dis[x]+a[x][i]) && d[i]>d[x]+b[x][i]))
            {
            //    cout<<"                "<<x<<" "<<i<<" "<<a[x][i]+dis[x]<<endl;
                dis[i]=dis[x]+a[x][i]; d[i]=d[x]+b[x][i];
                if (!vis[i]) vis[i]=1,q.push(i);
            }
        }    
        //|| (dis[i]==dis[x]+a[x][i] && d[i]>d[x]+b[x][i])
    }    
}
int main()
{
    s=read(); t=read(); n=read();
    for (int i=1; i<=1000; i++)    
        for (int j=1; j<=1000; j++) a[i][j]=inf;
    for (int i=1; i<=n; i++)
    {
        int len=read(),cnt=read();  
        for (int j=1; j<=cnt; j++) c[j]=read(),m=max(m,c[j]);
        for (int j=1; j<=cnt; j++)
            for (int k=j+1; k<=cnt; k++)
            if (a[c[j]][c[k]]>len || ((a[c[j]][c[k]]==len) && (b[c[j]][c[k]]>(k-j)))) a[c[j]][c[k]]=len,b[c[j]][c[k]]=k-j;
    }
    spfa();
    if (dis[t]==inf) dis[t]=-1,d[t]=-1;
    cout<<dis[t]<<" "<<d[t]<<endl;
    return 0;
}

View Code

2016.11.12

BZOJ3887: spfa（正边一次+反边一次）

BZOJ3886：状态压缩dp+二分（f[i]表示看电影状态为i的最长连续时间）

BZOJ4098：DP优化（f[i][j][k][l]：（i+j）==（k+l）优化为f[i][j][k]：（i+j)满足滚动数组

BZOJ3888：把时间求出来+线段树

BZOJ3887

#include<algorithm>
#include<iostream>
#include<cstring>
#include<cstdio>
#include<cmath>
#include<queue>
#define N 100005
#define M 200005
using namespace std;
int read()
{
    int x=0,f=1; char ch;
    while (ch=getchar(),ch<'0'||ch>'9') if (ch=='-') f=-1;
    while (x=x*10+ch-'0',ch=getchar(),ch>='0'&&ch<='9');
    return x*f;
}
int n,m;
int a[N],b[N];
int tot,pre[M],v[M],now[N];
int bel[N],low[N],dfn[N],num[N],total,ind,top,z[N];
int dist1[N],dist2[N];
bool inq[N],vis[N];
queue<int> q;
void ins(int a,int b){++tot; pre[tot]=now[a]; now[a]=tot; v[tot]=b;}
void tarjan(int x)
{
    low[x]=dfn[x]=++ind;
    ++top; z[top]=x; inq[x]=1;
    for (int p=now[x]; p; p=pre[p])
    {
        int son=v[p];
        if (!dfn[son]) tarjan(son),low[x]=min(low[x],low[son]);
        else if (inq[son]) low[x]=min(low[x],dfn[son]); 
    }
    if (low[x]==dfn[x])
    {
        ++total; num[total]=1; inq[x]=0; bel[x]=total;
        while (z[top]!=x)
        {
            int son=z[top]; bel[son]=total; inq[son]=0; num[total]++; top--;
        }
        top--;
    }
}
void build(int X)
{
    memset(now,0,sizeof(now)); tot=0;
    for (int i=1; i<=m; i++)
    {
        int x=a[i],y=b[i]; 
        if (bel[x]!=bel[y]) 
        {
            if (X==1) ins(bel[x],bel[y]); else ins(bel[y],bel[x]);
        }
    }
}
void spfa1()
{
    vis[bel[1]]=1; dist1[bel[1]]=num[bel[1]]; q.push(bel[1]);
    while (!q.empty())
    {
        int x=q.front(); q.pop(); vis[x]=0;
        for (int p=now[x]; p; p=pre[p])
        {
            int son=v[p];
            if (dist1[son]<dist1[x]+num[son]) 
            {
                dist1[son]=dist1[x]+num[son];
                if (!vis[son]) q.push(son),vis[son]=1;
            }
        }
    }
}
void spfa2()
{
    vis[bel[1]]=1; dist2[bel[1]]=num[bel[1]]; q.push(bel[1]);
    while (!q.empty())
    {
        int x=q.front(); q.pop(); vis[x]=0;
        for (int p=now[x]; p; p=pre[p])
        {
            int son=v[p];
            if (dist2[son]<dist2[x]+num[son]) 
            {
                dist2[son]=dist2[x]+num[son];
                if (!vis[son]) q.push(son),vis[son]=1;
            }
        }
    }
}
int main()
{
    n=read(); m=read();
    for (int i=1; i<=m; i++) a[i]=read(),b[i]=read(),ins(a[i],b[i]);
    for (int i=1; i<=n; i++) if (!dfn[i]) tarjan(i);
    build(1); spfa1();
    build(2); spfa2();
    int ans=0;
    for (int i=1; i<=m; i++) if (bel[a[i]]!=bel[b[i]] && dist1[bel[b[i]]] && dist2[bel[a[i]]]) 
    {
        ans=max(ans,dist1[bel[b[i]]]+dist2[bel[a[i]]]-num[bel[1]]);
    }
    printf("%d\n",ans);
    return 0;
}

BZOJ3886


#include<iostream>
#include<algorithm>
#include<cstring>
#include<cstdio>
#include<cmath>
using namespace std;
int n,L;
int num[25],len[25],c[25][1005];
int f[1100000];
int read()
{
    int x=0,f=1; char ch; 
    while (ch=getchar(),ch<'0'||ch>'9') if (ch=='-') f=-1;
    while (x=x*10+ch-'0',ch=getchar(),ch>='0'&&ch<='9');
    return x*f;
}
int find(int x,int s)
{
    int l=1,r=num[x],Ans=-1;
    while (l<=r)
    {
        int mid=(l+r)>>1;
        if (c[x][mid]<=s) Ans=mid,l=mid+1; else r=mid-1;
    }
    return Ans;
}
int main()
{
    n=read(); L=read();
    for (int i=1; i<=n; i++)
    {
        len[i]=read(); num[i]=read();
        for (int j=1; j<=num[i]; j++) c[i][j]=read();    
    } 
    f[0]=0;
    int s=1<<n,ans=0x7fffffff;
    for (int i=1; i<s; i++) f[i]=-1;
    for (int i=0; i<s; i++)
    {
        if (f[i]==-1) continue;
        int k=0;
        if (f[i]>L) 
        {
            for (int j=i; j; j>>=1) if (j&1) k++;
            ans=min(ans,k); continue;
        }
        for (int j=1; j<=n; j++)
        {
            if (i&(1<<(j-1))) continue;
            int k=find(j,f[i]); if (k==-1) continue;
            f[i|(1<<(j-1))]=max(f[i|(1<<(j-1))],c[j][k]+len[j]);
        }
    }
    if (ans==0x7fffffff) ans=-1;
    printf("%d\n",ans);
    return 0;
}

BZOJ4098

#include<iostream>
#include<algorithm>
#include<cstring>
#include<cstdio>
#include<cmath>
#define N 505
#define mod 1000000007
#define add(a,b) (a=(a+b)%mod)
using namespace std;
int n,f[2][N][N];
char s[N][N];
int main()
{
    scanf("%d",&n);
    for (int i=1; i<=n; i++) scanf("%s",s[i]+1);
    if(s[1][1]!=s[n][n])
    {
        puts("0");
        return 0;
    }
    int now=1,last=0;
    f[now][0][0]=1;
    for (int h=0; h<n; h++)
    {
        now^=1; last^=1;
        memset(f[now],0,sizeof(f[now]));
        for (int i=0; i<=h; i++)
        {
            int j=(h-i),a=i+1,b=j+1;
            for (int k=0; k<=h; k++)
            {
                int l=h-k,x=n-l,y=n-k;
            /*    if (s[a+1][b]==s[x][y-1]) (f[now][i+1][k+1]+=f[last][i][k])%mod;
                if (s[a+1][b]==s[x-1][y]) (f[now][i+1][k]+=f[last][i][k])%mod;
                if (s[a][b+1]==s[x][y-1]) (f[now][i][k+1]+=f[last][i][k])%mod;
                if (s[a][b+1]==s[x-1][y]) (f[now][i][k]+=f[last][i][k])%mod;    */ 
                if(s[a+1][b]==s[x-1][y])add(f[now][i+1][ k ],f[last][i][k]);
                if(s[a+1][b]==s[x][y-1])add(f[now][i+1][k+1],f[last][i][k]);
                if(s[a][b+1]==s[x-1][y])add(f[now][ i ][ k ],f[last][i][k]);
                if(s[a][b+1]==s[x][y-1])add(f[now][ i ][k+1],f[last][i][k]);
            } 
        }
    }
    int ans=0;
    for (int i=0; i<n; i++) add(ans,f[last][i][i]);
    printf("%d\n",ans);
    return 0;
}

BZOJ3888

#include<iostream>
#include<algorithm>
#include<cstring>
#include<cstdio>
#include<cmath>
#define N 50005
using namespace std;
int n,tot;
struct data{
    int h,l,r;
}a[N];
int b[2*N],cov[N*8];
int read()
{
    int x=0,f=1; char ch;
    while (ch=getchar(),ch<'0'||ch>'9') if (ch=='-') f=-1;
    while (x=x*10+ch-'0',ch=getchar(),ch>='0'&&ch<='9');
    return x*f;
}
bool cmp2(data a,data b){return a.h<b.h;
}
int get(int x,int c)
{
    return x>=0?0:-x*c;
}
int cover(int k,int l,int r,int x,int y)
{
    if (cov[k]) return 0;
    if (x<=l && r<=y)
    {
        cov[k]=1; return 1;
    }
    bool ret=0;
    int mid=(l+r)>>1;
    if (x<=mid) ret|=cover(k*2,l,mid,x,y);
    if (mid<y) ret|=cover(k*2+1,mid+1,r,x,y);
    cov[k]=cov[k*2]&cov[k*2+1];
    return ret;
}
int find(int x)
{
    int l=1,r=tot,ans=0;
    while (l<=r)
    {
        int mid=(l+r)>>1;
        if (b[mid]<=x) ans=mid,l=mid+1; else r=mid-1;
    }
    return ans;
}
int main()
{
    n=read();
    for (int i=1; i<=n; i++)
    {
        int x=read(),y=read(),c=read();
        int l=get(x+1,c),r=get(x,c);
        a[i].l=l,a[i].r=r,a[i].h=y; 
        b[++tot]=l; b[++tot]=r;
    }
    sort(b+1,b+tot+1);
    for (int i=1; i<=n; i++) a[i].l=find(a[i].l),a[i].r=find(a[i].r)-1;
    sort(a+1,a+n+1,cmp2);
    int ans=0;
    for (int i=1; i<=n; i++) ans+=cover(1,1,tot,a[i].l,a[i].r);
    printf("%d\n",ans);
    return 0;
}

View Code

2016.11.11

BZOJ4396 ：贪心

BZOJ4397 ：前缀和

BZOJ3943 ：最小生成树

BZOJ4576：DP：这道题还可以网上有很多种写法

BZOJ4582：DP：之前看错题想了好久最后发现题目意思好水

BZOJ4412：贪心：这道题也不错，我们首先将每个数减1，如果存在j-->x的子段和大于0，

　　　　　　　　　则说明一定有牛走出去，而我们可以知道在顺时针方向一定存在一个

　　　　　　　　　点没有牛越过去，于是我们找到那个点将环转化为链即可，而这个点

　　　　　　　　　一定是最大子段和的左节点，于是问题解决

2016.11.10

BZOJ1592 Usaco2008 Feb]Making the Grade 路面修整：离散+DP

BZOJ1051 HAOI 受欢迎的牛：tarjan

BZOJ2442 修建草坪：单调队列优化DP

BZOJ3890 Meeting time : 分层DP

BZOJ4390 Max Flow ：树上差分

BZOJ4525 ：二分答案判定

BZOJ4511 ：DP

  1 BZOJ1592
  2 
  3 #include<iostream>
  4 #include<algorithm>
  5 #include<cstring>
  6 #include<cstdio>
  7 #include<cmath>
  8 #define N 3005
  9 #define inf 0x7fffffff
 10 using namespace std;
 11 int n,m,ans,a[N],c[N],f[N][N];
 12 int read()
 13 {
 14   int x=0,f=1; char ch;
 15   while (ch=getchar(),ch<'0'||ch>'9') if (ch=='-') f=-1;
 16   while (x=x*10+ch-'0',ch=getchar(),ch>='0' && ch<='9');
 17   return x*f;
 18 }
 19 void solve()
 20 {
 21   sort(c+1,c+n+1);
 22   m=unique(c+1,c+n+1)-(c+1);
 23   for (int i=1; i<=n; i++) f[i][0]=inf/2;
 24   for (int i=1; i<=n; i++)
 25     {
 26       for (int j=1; j<=m; j++)
 27     {
 28       f[i][j]=min(f[i-1][j]+abs(a[i]-c[j]),f[i][j-1]);
 29     }
 30     }
 31   ans=f[n][m];
 32   for (int i=1; i<=n; i++) f[i][m+1]=inf/2;
 33   for (int i=1; i<=n; i++)
 34     {
 35       for (int j=m; j>=1; j--)
 36     {
 37       f[i][j]=min(f[i-1][j]+abs(a[i]-c[j]),f[i][j+1]);
 38     }
 39     }
 40   ans=min(ans,f[n][1]);
 41 }
 42 int main()
 43 {
 44   n=read();
 45   for (int i=1; i<=n; i++)  c[i]=a[i]=read();
 46   solve();
 47   printf("%d\n",ans);
 48   return 0;
 49 }
 50 
 51 BZOJ1051
 52 
 53 #include<iostream>
 54 #include<cstring>
 55 #include<algorithm>
 56 #include<cmath>
 57 #include<cstdio>
 58 #define ll long long
 59 #define N 10005
 60 #define M 50005
 61 using namespace std;
 62 int n,m,ans,u[M],V[M];
 63 int now[N],pre[M],v[M],tot;
 64 int ind,top,total,z[N],dfn[N],low[N],num[N],in[N],out[N],belong[N];
 65 bool vis[N],inq[N];
 66 int read()
 67 {
 68     int x=0,f=1; char ch;
 69     while (ch=getchar(),ch<'0'||ch>'9') if (ch=='-') f=-1;
 70     while (x=x*10+ch-'0',ch=getchar(),ch>='0'&&ch<='9');
 71     return x*f;
 72 }
 73 void ins(int a,int b){
 74     ++tot; pre[tot]=now[a]; now[a]=tot; v[tot]=b;
 75 }
 76 void dfs(int x)
 77 {
 78     
 79     dfn[x]=low[x]=++ind;
 80     vis[x]=inq[x]=1; z[++top]=x;
 81     for (int p=now[x]; p; p=pre[p])
 82     {
 83         int son=v[p];
 84         if (!dfn[son]) {dfs(son); low[x]=min(low[x],low[son]);}
 85         else if (inq[son]) low[x]=min(low[x],dfn[son]);
 86     }
 87     if (low[x]==dfn[x])
 88     {
 89         ++total;
 90         belong[x]=total; inq[x]=0; num[total]=1;
 91         while (z[top]!=x)
 92         {
 93             int son=z[top];
 94             belong[son]=total; inq[son]=0; num[total]++;
 95             top--;
 96         }
 97         top--;
 98     }
 99 }
100 int main()
101 {
102     n=read(); m=read();
103     for (int i=1; i<=m; i++)
104     {
105         int x=read(),y=read();
106         u[i]=x; V[i]=y;
107         ins(x,y); 
108     }
109     for (int i=1; i<=n; i++) if (!dfn[i]) dfs(i);
110     for (int i=1; i<=m; i++) if (belong[u[i]]!=belong[V[i]])
111     {
112     //    cout<<" "<<belong[u[i]]<<" "<<belong[V[i]]<<endl;
113         ++out[belong[u[i]]]; ++in[belong[V[i]]];
114     }
115 //    for (int i=1; i<=total; i++) cout<<num[i]<<endl;
116     int sum=0;
117     for (int i=1; i<=total; i++)
118     {
119         if (!out[i]) {ans=num[i]; sum++; if (sum>=2) break;}
120     }
121 //    cout<<ans<<endl;
122     if (sum>1) ans=0; printf("%d\n",ans);
123     return 0;
124 }
125 
126 BZOJ 2442
127 
128 #include<iostream>
129 #include<cstring>
130 #include<algorithm>
131 #include<cmath>
132 #include<cstdio>
133 #define ll long long
134 #define N 100005
135 using namespace std;
136 int n,k,head,tail;
137 ll ans,sum,f[N];
138 int a[N],pos[N];
139 int read()
140 {
141     int x=0,f=1; char ch;
142     while (ch=getchar(),ch<'0'||ch>'9') if (ch=='-') f=-1;
143     while (x=x*10+ch-'0',ch=getchar(),ch>='0'&&ch<='9');
144     return x*f;
145 }
146 int main()
147 {
148     n=read(); k=read(); 
149     for (int i=1; i<=n; i++) a[i]=read(),sum+=a[i];
150     for (int i=1; i<=n; i++)
151     {
152         while (head<=tail && pos[head]<i-k-1) head++;
153         f[i]=f[pos[head]]+a[i];
154         while (head<=tail && f[pos[tail]]>=f[i]) tail--;
155         ++tail; pos[tail]=i; 
156     }
157     ans=100000000000000;
158     for (int i=n-k; i<=n; i++) ans=min(ans,f[i]);
159     printf("%lld\n",sum-ans);
160     return 0;
161 }
162 
163 BZOJ3890
164 
165 #include<iostream>
166 #include<cstring>
167 #include<algorithm>
168 #include<cmath>
169 #include<cstdio>
170 #define N 105
171 #define M (N*(N+1))
172 #define ll long long
173 using namespace std;
174 int pre[M],v[M],val1[M],val2[M],now[N],n,m,tot;
175 bool f[N][M],g[N][M];
176 int read()
177 {
178     int x=0,f=1; char ch;
179     while (ch=getchar(),ch<'0'||ch>'9') if (ch=='-') f=-1;
180     while (x=x*10+ch-'0',ch=getchar(),ch>='0'&&ch<='9');
181     return x*f;
182 }
183 void ins(int a,int b,int c,int d)
184 {
185     ++tot; pre[tot]=now[a]; now[a]=tot; v[tot]=b; val1[tot]=c; val2[tot]=d; 
186 }
187 int main()
188 {
189     n=read(); m=read();
190     for (int i=1; i<=m; i++)
191     {
192         int u=read(),v=read(),a=read(),b=read();
193         ins(u,v,a,b);
194     }
195     f[1][0]=g[1][0]=1;
196     for (int i=1; i<=n-1; i++)
197     {
198         for (int p=now[i]; p; p=pre[p])
199         {
200             int son=v[p];
201             for (int j=val1[p]; j<=10000; j++) f[son][j]|=f[i][j-val1[p]];
202             for (int j=val2[p]; j<=10000; j++) g[son][j]|=g[i][j-val2[p]];
203         }
204     }
205     bool bo=false;
206     for (int i=0; i<=10000; i++)
207     if (g[n][i] && f[n][i])
208     {
209         bo=true;
210         printf("%d\n",i);
211         break;
212     }
213     if (!bo) printf("IMPOSSIBLE\n"); 
214     return 0;
215  } 
216 
217 BZOJ4390
218 
219 #include<iostream>
220 #include<cstring>
221 #include<algorithm>
222 #include<cmath>
223 #include<cstdio>
224 #define N 60005
225 #define M N*2
226 #define ll long long
227 using namespace std;
228 int pre[M],v[M],now[N],tot,n,k,ans;
229 int f[N][25],bin[25],deep[N],val[N];
230 int read()
231 {
232     int x=0,f=1; char ch;
233     while (ch=getchar(),ch<'0'||ch>'9') if (ch=='-') f=-1;
234     while (x=x*10+ch-'0',ch=getchar(),ch>='0'&&ch<='9');
235     return x*f;
236 }
237 void ins(int a,int b){++tot; pre[tot]=now[a]; now[a]=tot; v[tot]=b; 
238 }
239 void dfs(int x)
240 {
241      for (int i=1; i<=19 && bin[i]<=deep[x]; i++) f[x][i]=f[f[x][i-1]][i-1];
242      for (int p=now[x]; p; p=pre[p])
243      {
244          int son=v[p]; if (son==f[x][0]) continue;
245          deep[son]=deep[x]+1; f[son][0]=x;
246          dfs(son);
247      }
248 }
249 int lca(int x,int y)
250 {
251     if (deep[x]<deep[y]) swap(x,y);
252     int t=deep[x]-deep[y];
253     for (int i=0; bin[i]<=t; i++)
254     {
255         if (t&bin[i]) x=f[x][i];
256     }
257     for (int i=19; i>=0; i--) if (f[x][i]!=f[y][i]) x=f[x][i],y=f[y][i];
258     if (x==y) return x;
259     return f[x][0];
260 }
261 void dfs2(int x,int fa)
262 {
263     for (int p=now[x]; p; p=pre[p])
264     {
265         int son=v[p]; if (son==fa) continue;
266         dfs2(son,x); val[x]+=val[son];
267     }
268     ans=max(ans,val[x]);
269 }
270 int main()
271 {
272     n=read(); k=read();
273     for (int i=1; i<n; i++)
274     {
275         int x=read(),y=read();
276         ins(x,y); ins(y,x);
277     }
278     bin[0]=1; for (int i=1; i<=20; i++) bin[i]=bin[i-1]*2;
279     deep[1]=1; dfs(1);
280     for (int i=1; i<=k; i++)
281     {
282         int x=read(),y=read();
283         int t=lca(x,y);
284         val[x]++; val[y]++; val[t]--; val[f[t][0]]--;
285     }
286     dfs2(1,0);
287     printf("%d\n",ans);
288     return 0;
289 }
290 
291 
292 BZOJ4525
293 
294 #include<iostream>
295 #include<cstring>
296 #include<algorithm>
297 #include<cmath>
298 #include<cstdio>
299 #define ll long long
300 #define inf 0x7ffffff
301 using namespace std;
302 int n,k,ans;
303 int a[50005];
304 int read()
305 {
306     int x=0,f=1; char ch;
307     while (ch=getchar(),ch<'0'||ch>'9') if (ch=='-') f=-1;
308     while (x=x*10+ch-'0',ch=getchar(),ch>='0'&&ch<='9');
309     return x*f;
310 }
311 bool pd(int mid)
312 {
313     int l=0;
314     for (int i=1; i<=k; i++)
315     {
316         int pos=a[l+1];
317         while (l+1<=n && ((a[l+1]-pos)<=2*mid)) l++;
318     }
319     if (l>=n) return true;
320     return false;
321 }
322 int main()
323 {
324     n=read(); k=read();
325     for (int i=1; i<=n; i++) a[i]=read();
326     sort(a+1,a+n+1);
327     int l=0,r=inf-2;
328     while (l<=r)
329     {
330         int mid=(l+r)>>1;
331         if (pd(mid)) ans=mid,r=mid-1; else l=mid+1;
332     }
333     printf("%d\n",ans);
334     return 0;
335 }
336 
337 BZOJ4511
338 
339 
340 #include<iostream>
341 #include<cstring>
342 #include<algorithm>
343 #include<cmath>
344 #include<cstdio>
345 #define ll long long
346 #define N 50005
347 using namespace std;
348 int ans,n,a[N],f[N][8];
349 int read()
350 {
351     int x=0,f=1; char ch;
352     while (ch=getchar(),ch<'0'||ch>'9') if (ch=='-') f=-1;
353     while (x=x*10+ch-'0',ch=getchar(),ch>='0'&&ch<='9');
354     return x*f;
355 }
356 int main()
357 {
358     n=read();
359     for (int i=1; i<=n; i++) a[i]=read()%7;
360     memset(f,-1,sizeof(f));
361     f[0][0]=0; for (int i=1; i<=n; i++) f[i][a[i]]=1;
362     for (int i=1; i<=n; i++)
363         for (int j=0; j<=6; j++)
364         if (f[i-1][j]!=-1) f[i][(j+a[i])%7]=max(f[i][(j+a[i])%7],f[i-1][j]+1);
365     for (int i=1; i<=n; i++) ans=max(ans,f[i][0]);
366     printf("%d\n",ans);
367     return 0;
368 }

代码集合

2016.11.9

BZOJ1711：最大流

BZOJ1642: 排序+DP

  1 BZOJ1711
  2 
  3 #include<iostream>
  4 #include<cstring>
  5 #include<algorithm>
  6 #include<cmath>
  7 #include<cstdio>
  8 #include<queue>
  9 #define inf 0x7fffffff
 10 #define ll long long
 11 #define N 505
 12 #define M 50005
 13 using namespace std;
 14 int n,F,D,head,tail,list[N<<2],tot=1,S,T,ans=0;
 15 int pre[M],v[M],cap[M],now[N],deep[N];
 16 queue<int>q;
 17 int read()
 18 {
 19     int x=0,f=1; char ch;
 20     while (ch=getchar(),ch<'0'||ch>'9') if (ch=='-') f=-1;
 21     while (x=x*10+ch-'0',ch=getchar(),ch>='0'&&ch<='9');
 22     return x*f;
 23 }
 24 void ins(int a,int b,int c){
 25     ++tot; pre[tot]=now[a]; now[a]=tot; v[tot]=b; cap[tot]=c;
 26     ++tot; pre[tot]=now[b]; now[b]=tot; v[tot]=a; cap[tot]=0;
 27 }
 28 void init_build()
 29 {
 30     n=read(); F=read(); D=read();
 31     S=0; T=n*2+F+D+1;
 32     for (int i=1; i<=F; i++) ins(S,i,1);
 33     for (int i=F+n*2+1; i<=F+n*2+D; i++) ins(i,T,1);
 34     for (int i=1; i<=n; i++)
 35     {
 36         int A=read(),B=read();
 37         for (int j=1; j<=A; j++) {int x=read(); ins(x,F+i,1);}
 38         for (int j=1; j<=B; j++) {int x=read(); ins(F+n+i,F+n*2+x,1);}
 39     }
 40     for (int i=1;i<=n;i++) ins(F+i,F+i+n,1);
 41 }
 42 bool bfs()
 43 {
 44     for (int i=S;i<=T;i++) deep[i]=-1; 
 45     deep[S]=0; head=0,tail=1,list[1]=S;
 46     while (head<tail)
 47     {
 48         int x=list[++head];
 49         for (int p=now[x]; p; p=pre[p])
 50         {
 51             int son=v[p];
 52             if (cap[p] && deep[son]==-1)
 53             {
 54                 deep[son]=deep[x]+1;
 55                 if (son==T) return 1;
 56                 list[++tail]=son;
 57             }
 58         }
 59     }
 60     return 0;
 61 }
 62 int find(int x,int tmpflow)
 63 {
 64     int temp,re;
 65     if (x==T) return tmpflow;
 66     re=temp=0;
 67     for (int p=now[x]; p; p=pre[p])
 68     {
 69         int son=v[p]; 
 70         if (cap[p] && deep[son]==deep[x]+1)
 71         {
 72             temp=find(son,min(tmpflow,cap[p]));
 73             cap[p]-=temp;
 74             cap[p^1]+=temp;
 75             re+=temp;
 76             tmpflow-=temp;
 77             if (tmpflow==0) break;
 78         }
 79     }
 80     deep[x]=-1;
 81     return re;
 82 }
 83 void dinic()
 84 {
 85     ans=0;
 86     while (bfs())
 87     {
 88         ans+=find(S,inf);
 89     }
 90 }
 91 int main()
 92 {
 93     tot=1;
 94     init_build();
 95     dinic();
 96     printf("%d\n",ans);
 97     return 0;
 98 }
 99 
100 BZOJ 1642
101 
102 #include<iostream>
103 #include<cstring>
104 #include<cmath>
105 #include<cstdio>
106 #include<algorithm>
107 using namespace std;
108 int n,m,r,ans=0;
109 int read(){
110   int x=0,f=1; char ch;
111   while (ch=getchar(),ch<'0'||ch>'9') if (ch=='-') f=-1;
112   while (x=x*10+ch-'0',ch=getchar(),ch>='0'&&ch<='9');
113   return x*f;
114 }
115 struct data{
116   int l,r,val;
117 }a[1005];
118 int f[1005];
119 bool cmp(data a,data b)
120 {
121   return a.l==b.l?a.r<b.r:a.l<b.l;
122 }
123 int main()
124 {
125   n=read(); m=read()+1; r=read();
126   a[1].l=a[1].r=-100; a[1].val=0;
127   for (int i=2; i<=m; i++)
128     {
129       a[i].l=read(),a[i].r=read()-1,a[i].val=read();
130     }
131   sort(a+1,a+m+1,cmp);
132   for (int i=2; i<=m; i++)
133     {
134       for (int j=1; j<=i-1; j++)
135     {
136       if (a[j].r+r<a[i].l)
137         {
138           f[i]=max(f[i],f[j]+a[i].val);
139           ans=max(ans,f[i]);
140         }
141     }
142     }
143   printf("%d\n",ans);
144   return 0;
145 }

代码集合

2016.11.8

BZOJ1708：背包

BZOJ1690：01分数规划+spfa+二分

BZOJ1669：LIS问题+单调栈

  1 BZOJ 1708
  2 
  3 #include<iostream>
  4 #include<cstring>
  5 #include<algorithm>
  6 #include<cmath>
  7 #include<cstdio>
  8 #define ll long long
  9 using namespace std;
 10 int n,m;
 11 ll f[10005];
 12 int read()
 13 {
 14     int x=0,f=1; char ch;
 15     while (ch=getchar(),ch<'0'||ch>'9') if (ch=='-') f=-1;
 16     while (x=x*10+ch-'0',ch=getchar(),ch>='0'&&ch<='9');
 17     return x*f;
 18 }
 19 int main()
 20 {
 21     n=read(); m=read(); f[0]=1;
 22     for (int i=1; i<=n; i++)
 23     {
 24         int x=read();
 25         for (int i=x; i<=m; i++) f[i]+=f[i-x];
 26     }
 27     printf("%lld\n",f[m]);
 28     return 0;
 29 }
 30 
 31 
 32 BZOJ1690
 33 #include<iostream>
 34 #include<cstring>
 35 #include<algorithm>
 36 #include<cmath>
 37 #include<cstdio>
 38 #define ll long long
 39 #define N 1005
 40 #define M 5005
 41 using namespace std;
 42 int n,m,tot;
 43 int a[N],now[N],pre[M],v[M];
 44 double ans,mid,val[M],value[N],dis[N];
 45 bool vis[N];
 46 int read()
 47 {
 48     int x=0,f=1; char ch;
 49     while (ch=getchar(),ch<'0'||ch>'9') if (ch=='-') f=-1;
 50     while (x=x*10+ch-'0',ch=getchar(),ch>='0'&&ch<='9');
 51     return x*f;
 52 }
 53 void ins(int a,int b,int c){++tot; pre[tot]=now[a]; now[a]=tot; v[tot]=b; val[tot]=c;
 54 }
 55 bool spfa(int x)
 56 {
 57     vis[x]=1;
 58     for (int p=now[x]; p; p=pre[p])
 59     {
 60         int son=v[p];
 61         if (dis[son]<dis[x]+value[son]-mid*val[p])
 62         {
 63             if (!vis[son])
 64             {
 65                 dis[son]=dis[x]+value[son]-mid*val[p];
 66                 if (spfa(son)) return 1;
 67              }
 68             else return 1;
 69         }
 70     }
 71     return vis[x]=0;
 72 }
 73 int main()
 74 {
 75     n=read(); m=read();
 76     for (int i=1; i<=n; i++) value[i]=read();
 77     for (int i=1; i<=m; i++)
 78     {
 79         int a=read(),b=read(),c=read(); ins(a,b,c);
 80     }
 81     double l=0,r=1000,eps=1e-3;
 82     while (r-l>eps)
 83     {
 84         memset(dis,254,sizeof(dis));
 85         memset(vis,0,sizeof(vis));
 86         mid=(l+r)/2.0; dis[1]=0.0;
 87         if (spfa(1)) ans=mid,l=mid; else r=mid;
 88      } 
 89      printf("%0.2lf\n",ans); 
 90     return 0;
 91 }
 92 
 93 
 94 BZOJ1669
 95 
 96 #include<iostream>
 97 #include<cstring>
 98 #include<algorithm>
 99 #include<cmath>
100 #include<cstdio>
101 #define N 5005
102 #define ll long long
103 using namespace std;
104 int n,tot;
105 int b[N];
106 int read()
107 {
108     int x=0,f=1; char ch;
109     while (ch=getchar(),ch<'0'||ch>'9') if (ch=='-') f=-1;
110     while (x=x*10+ch-'0',ch=getchar(),ch>='0'&&ch<='9');
111     return x*f;
112 }
113 int main()
114 {
115     int n=read(),tot=0;
116     for (int i=1; i<=n; i++)
117     {
118         int x=read();
119         if (x>b[tot]) 
120         {
121             tot++; b[tot]=x; 
122         }
123         else
124         {
125             int l=tot;
126             while (l>=1 && b[l]>=x) l--;
127             //cout<<" "<<l<<endl;
128             b[l+1]=x;
129         }
130     }
131     printf("%d\n",tot);
132     return 0;
133 }

代码集合

2016.11.7

BZOJ3298：打表找规律

BZOJ3296：并查集

BZOJ1599：模拟

BZOJ1232：最小生成树

  1 BZOJ3298
  2 
  3 
  4 #include<iostream>
  5 #include<cstring>
  6 #include<algorithm>
  7 #include<cmath>
  8 #include<cstdio>
  9 #define ll long long
 10 #define N 1000005
 11 using namespace std;
 12 int n,m,f[N];
 13 int read()
 14 {
 15     int x=0,f=1; char ch;
 16     while (ch=getchar(),ch<'0'||ch>'9') if (ch=='-') f=-1;
 17     while (x=x*10+ch-'0',ch=getchar(),ch>='0'&&ch<='9');
 18     return x*f;
 19 }
 20 int main()
 21 {
 22     n=read()+1; m=read()+1;
 23     f[1]=1; int t=0;
 24     for (int i=2; i<=m; i++)
 25     {
 26         if (f[i]) continue;
 27         t++; f[i]=i+t; if (i+t<=m) f[i+t]=i;
 28      } 
 29      int T=read();
 30      while (T--)
 31      {
 32          int x=read()+1,y=read()+1;
 33          if (f[x]==y) printf("Farmer John\n"); else printf("Bessie\n");
 34      }
 35     return 0;
 36  } 
 37 
 38 
 39 BZOJ3296
 40 
 41 #include<iostream>
 42 #include<cstring>
 43 #include<algorithm>
 44 #include<cmath>
 45 #include<cstdio>
 46 #define ll long long
 47 #define N 40005
 48 using namespace std;
 49 int fa[N],id[N],n,m,ans;
 50 int read()
 51 {
 52     int x=0,f=1; char ch;
 53     while (ch=getchar(),ch<'0'||ch>'9') if (ch=='-') f=-1;
 54     while (x=x*10+ch-'0',ch=getchar(),ch>='0'&&ch<='9');
 55     return x*f;
 56 }
 57 int find(int x){return x==fa[x]?x:fa[x]=find(fa[x]);
 58 }
 59 int main()
 60 {
 61     n=read(); m=read();
 62     for (int i=1; i<=n; i++) fa[i]=i;
 63     for (int i=1; i<=n; i++)
 64     {
 65         int k=read();
 66         for (int j=1; j<=k; j++){int x=read(); if (!id[x]) id[x]=i; else {fa[find(id[x])]=find(i); id[x]=i;}}
 67     }
 68     for (int i=1; i<=n; i++) if (find(i)==i) ans++;
 69     printf("%d\n",ans-1);
 70     return 0;
 71 }
 72 
 73 
 74 BZOJ1599
 75 
 76 #include<iostream>
 77 #include<cstring>
 78 #include<algorithm>
 79 #include<cmath>
 80 #include<cstdio>
 81 #define ll long long
 82 using namespace std;
 83 int sum[105],ans;
 84 int read()
 85 {
 86     int x=0,f=1; char ch;
 87     while (ch=getchar(),ch<'0'||ch>'9') if (ch=='-') f=-1;
 88     while (x=x*10+ch-'0',ch=getchar(),ch>='0'&&ch<='9');
 89     return x*f;
 90 }
 91 int main()
 92 {    
 93     int a=read(),b=read(),c=read();
 94     for (int i=1; i<=a; i++)
 95         for (int j=1; j<=b; j++)
 96             for (int k=1; k<=c; k++) sum[i+j+k]++;
 97     sum[0]=0; ans=0; for (int i=3; i<=a+b+c; i++) if (sum[i]>sum[ans]) ans=i;
 98     printf("%d\n",ans);
 99     return 0;
100 }
101 
102 
103 BZOJ1232
104 
105 #include<iostream>
106 #include<cstring>
107 #include<algorithm>
108 #include<cmath>
109 #include<cstdio>
110 #define ll long long
111 #define N 100005
112 using namespace std;
113 int n,m;
114 struct data{
115     int u,v,val;
116 }a[N];
117 int c[N],Min=0x7fffffff,ans=0,fa[N],cnt=0;
118 int read()
119 {
120     int x=0,f=1; char ch;
121     while (ch=getchar(),ch<'0'||ch>'9') if (ch=='-') f=-1;
122     while (x=x*10+ch-'0',ch=getchar(),ch>='0'&&ch<='9');
123     return x*f;
124 }
125 bool cmp(data a,data b){return a.val<b.val;
126 }
127 int find(int x) {return x==fa[x]?x:fa[x]=find(fa[x]);}
128 int main()
129 {
130     n=read(); m=read();
131     for (int i=1; i<=n; i++) fa[i]=i;
132     for (int i=1; i<=n; i++) c[i]=read();
133     for (int i=1; i<=m; i++) a[i].u=read(),a[i].v=read(),a[i].val=read()*2+c[a[i].u]+c[a[i].v];
134     sort(a+1,a+m+1,cmp);
135     for (int i=1; i<=m; i++)
136     {
137         int u=a[i].u,v=a[i].v,val=a[i].val;
138         int fu=find(u),fv=find(v);
139         if (fv!=fu)
140         {
141             fa[fv]=fu; Min=min(Min,min(c[u],c[v])); 
142             ans+=val; cnt++; if (cnt==n-1) break;
143         }
144     }
145     printf("%d\n",ans+Min);
146     return 0;
147 }

代码集合

posted @ 2016-11-10 23:10 ACist 阅读(327) 评论(0) 编辑收藏举报

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