USACO 补完（TJ）计划
1666: [Usaco2006 Oct]Another Cow Number Game 奶牛的数字游戏
模拟
1 #include <cstdio> 2 inline int read() 3 { 4 register int f=1,c=getchar(),k=0; 5 while (c<'0'||c>'9')c=='-'&&(f=-1),c=getchar(); 6 while (c>='0'&&c<='9')k=k*10+c-'0',c=getchar(); 7 return k*f; 8 } 9 int n,ans; 10 int main() 11 { 12 n=read(); 13 while (n!=1) 14 if (n&1)n=n*3+1,ans++;else n=n>>1,ans++; 15 printf("%d\n",ans); 16 }
1576: [Usaco2009 Jan]安全路经Travel
http://www.cnblogs.com/mczhuang/p/7688406.html
1 #include <cstdio> 2 #include <queue> 3 #include <algorithm> 4 inline void swap(int &a,int &b) 5 { 6 register int tmp=b; 7 b=a;a=tmp; 8 } 9 inline int read() 10 { 11 register int k=0,c=getchar(),f=1; 12 while (c<'0'||c>'9')c=='-'&&(f=-1),c=getchar(); 13 while (c>='0'&&c<='9')k=k*10+c-'0',c=getchar(); 14 return k*f; 15 } 16 const int maxn=500000+100,inf=1<<30; 17 struct edg{ 18 int x,too,del,nxt; 19 }edge[maxn]; 20 struct qaq{ 21 int dis,pos; 22 }; 23 struct mc{ 24 int a,b,len; 25 }e[maxn]; 26 bool v[maxn],used[maxn]; 27 int vis[maxn]; 28 int n,m,tot,tot2,a,b,c,dist[maxn],last[maxn],h[maxn]; 29 int fq[maxn],eg[maxn],fa[maxn]; 30 std::priority_queue<qaq>q; 31 bool operator<(qaq a,qaq b){return a.dis>b.dis;} 32 inline void add(int a,int b,int c) 33 { 34 edge[++tot].nxt=last[a]; 35 last[a]=tot; 36 edge[tot].too=b; 37 edge[tot].x=a; 38 edge[tot].del=c; 39 } 40 inline bool cmp(mc a,mc b) 41 { 42 return a.len<b.len; 43 } 44 int gf(int now) 45 { 46 return fa[now]==now?now:fa[now]=gf(fa[now]); 47 } 48 inline void spfa() 49 { 50 for (register int i=1;i<=n;i++)dist[i]=inf; 51 v[1]=1;dist[1]=0;q.push((qaq){0,1}); 52 while (!q.empty()) 53 { 54 register int now=q.top().pos;q.pop(); 55 for (register int i=last[now];i;i=edge[i].nxt) 56 { 57 if (dist[edge[i].too]>edge[i].del+dist[now]) 58 { 59 dist[edge[i].too]=dist[now]+edge[i].del; 60 fq[edge[i].too]=now; 61 eg[edge[i].too]=i; 62 if (!v[edge[i].too]) 63 { 64 v[edge[i].too]=1; 65 q.push((qaq){dist[edge[i].too],edge[i].too}); 66 } 67 } 68 } 69 v[now]=0; 70 } 71 } 72 int main() 73 { 74 tot=1; 75 n=read();m=read(); 76 for (register int i=1;i<=n;i++)fa[i]=i; 77 for (register int i=1;i<=m;i++)a=read(),b=read(),c=read(),add(a,b,c),add(b,a,c); 78 spfa(); 79 for (register int i=1;i<=n;i++)used[eg[i]]=used[eg[i]^1]=1; 80 for (register int i=1;i<=tot;i++) 81 if (!used[i]) 82 { 83 e[++tot2].a=edge[i].x;e[tot2].b=edge[i].too; 84 e[tot2].len=edge[i].del+dist[edge[i].x]+dist[edge[i].too]; 85 } 86 std::sort(e+1,e+tot2+1,cmp); 87 for(register int i=1;i<=tot2;i++) 88 { 89 register int a=e[i].a,b=e[i].b,f1=gf(a),f2=gf(b),lasta=0,lastb=0; 90 while (f1!=f2) 91 { 92 if (dist[a]<dist[b])swap(a,b),swap(f1,f2),swap(lasta,lastb); 93 if (!vis[a]) 94 { 95 vis[a]=i; 96 if (lasta)fa[lasta]=a; 97 }else if (lasta)fa[lasta]=f1; 98 lasta=f1;a=fq[lasta];f1=gf(a); 99 } 100 } 101 for (register int i=2;i<=n;i++) 102 if (!vis[i])printf("-1\n");else printf("%d\n",e[vis[i]].len-dist[i]); 103 }
1708: [Usaco2007 Oct]Money奶牛的硬币
完全背包
#include <cstdio> #define ll long long inline int read() { register int c=getchar(),k=0,f=1; while (c<'0'||c>'9')c=='-'&&(f=-1),c=getchar(); while (c>='0'&&c<='9')k=k*10+c-'0',c=getchar(); return k*f; } const int maxn=10000+10; ll f[maxn];int n,v,cur; int main() { v=read();n=read(); f[0]=1; for (register int i=1;i<=v;i++) { cur=read(); for (register int j=cur;j<=n;j++) f[j]+=f[j-cur]; } printf("%lld\n",f[n]); }
1699: [Usaco2007 Jan]Balanced Lineup排队
裸RMQ
1 #include <cstdio> 2 #include <cmath> 3 #include <iostream> 4 using namespace std; 5 inline int read() 6 { 7 register int c=getchar(),f=1,k=0; 8 while (c<'0'||c>'9')c=='-'&&(f=-1),c=getchar(); 9 while (c>='0'&&c<='9')k=k*10+c-'0',c=getchar(); 10 return k*f; 11 } 12 inline int max(int a,int b) 13 { 14 return a>b?a:b; 15 } 16 inline int min(int a,int b) 17 { 18 return a<b?a:b; 19 } 20 const int maxn=50010; 21 int mi[maxn][17],mx[maxn][17],n,q,a,b; 22 int main() 23 { 24 n=read();q=read(); 25 register int lg=log(n)/log(2); 26 for (register int i=1;i<=n;i++) 27 mi[i][0]=mx[i][0]=read(); 28 for (register int j=1;j<=lg;j++) 29 for (register int i=1;i<=n-(1<<j)+1;i++) 30 { 31 register int tmp=i+(1<<(j-1)); 32 mi[i][j]=min(mi[i][j-1],mi[tmp][j-1]); 33 mx[i][j]=max(mx[i][j-1],mx[tmp][j-1]); 34 } 35 for (register int i=1;i<=q;i++) 36 { 37 a=read();b=read(); 38 lg=log(b-a+1)/log(2); 39 printf("%d\n",max(mx[a][lg],mx[b-(1<<lg)+1][lg])-min(mi[a][lg],mi[b-(1<<lg)+1][lg])); 40 } 41 }
1715: [Usaco2006 Dec]Wormholes 虫洞
SPFA判负环
1 #include <cstdio> 2 #include <cstring> 3 inline int read() 4 { 5 register int f=1,c=getchar(),k=0; 6 while(c<'0'||c>'9')c=='-'&&(f=-1),c=getchar(); 7 while(c>='0'&&c<='9')k=k*10+c-'0',c=getchar(); 8 return k*f; 9 } 10 const int maxn=6300*2,inf=1<<30; 11 bool vis[maxn]; 12 int m,n,a,b,c,tot,w,last[maxn],to[maxn],nxt[maxn],del[maxn],dist[maxn],q[maxn],cnt[maxn]; 13 bool spfa(int s) 14 { 15 memset(cnt,0,sizeof(cnt)); 16 memset(vis,0,sizeof(vis)); 17 for (register int i=1;i<=n;i++) 18 dist[i]=inf; 19 register int front=1,rear=1; 20 dist[s]=0; 21 q[1]=s; 22 vis[s]=1; 23 while(front<=rear) 24 { 25 cnt[q[front]]++; 26 if (cnt[q[front]]>n)return 0; 27 for (register int i=last[q[front]];i;i=nxt[i]) 28 if (dist[q[front]]+del[i]<dist[to[i]]) 29 { 30 dist[to[i]]=dist[q[front]]+del[i]; 31 if (!vis[to[i]])q[++rear]=to[i],vis[to[i]]=1; 32 } 33 vis[q[front]]=0; 34 front++; 35 } 36 return 1; 37 } 38 void work() 39 { 40 n=read();m=read();w=read(); 41 tot=0; 42 memset(nxt,0,sizeof(nxt)); 43 memset(last,0,sizeof(last)); 44 memset(to,0,sizeof(to)); 45 for (register int i=1;i<=m;i++) 46 { 47 a=read();b=read();c=read(); 48 nxt[++tot]=last[a]; 49 last[a]=tot; 50 to[tot]=b; 51 del[tot]=c; 52 nxt[++tot]=last[b]; 53 last[b]=tot; 54 to[tot]=a; 55 del[tot]=c; 56 } 57 for (register int i=1;i<=w;i++) 58 { 59 a=read();b=read();c=-read(); 60 nxt[++tot]=last[a]; 61 last[a]=tot; 62 to[tot]=b; 63 del[tot]=c; 64 } 65 for (register int i=1;i<=n;i++) 66 if (!spfa(i)){printf("YES\n");return;} 67 printf("NO\n"); 68 } 69 int main() 70 { 71 int T=read(); 72 while(T--)work(); 73 }
1753: [Usaco2005 qua]Who's in the Middle
裸sort
1 #include <cstdio> 2 #include <algorithm> 3 inline int read() 4 { 5 register int f=1,c=getchar(),k=0; 6 while (c<'0'||c>'9')c=='-'&&(f=-1),c=getchar(); 7 while (c>='0'&&c<='9')k=k*10+c-'0',c=getchar(); 8 return k*=f; 9 } 10 const int maxn=1e4+1; 11 int n,a[maxn]; 12 int main() 13 { 14 n=read(); 15 for (register int i=1;i<=n;i++) 16 a[i]=read(); 17 std::sort(a+1,a+1+n); 18 printf("%d\n",a[n/2+1]); 19 }
1755: [Usaco2005 qua]Bank Interest
模拟
1 #include <cstdio> 2 inline int read() 3 { 4 register int f=1,c=getchar(),k=0; 5 while (c<'0'||c>'9')c=='-'&&(f=-1),c=getchar(); 6 while (c>='0'&&c<='9')k=k*10+c-'0',c=getchar(); 7 return k*f; 8 } 9 int main() 10 { 11 register int r,y; 12 register double tmp,tmp1; 13 r=read();tmp=read();y=read(); 14 tmp1=(double)r/100; 15 while(y--) 16 tmp*=1+tmp1; 17 printf("%d\n",(int)tmp); 18 }
3408: [Usaco2009 Oct]Heat Wave 热浪
SPFA
卡不动了QAQ
1 #include <cstdio> 2 inline void read(int &k) 3 { 4 register int f=1,c=getchar();k=0; 5 while(c<'0'||c>'9')c=='-'&&(f=-1),c=getchar(); 6 while(c>='0'&&c<='9')k=k*10+c-'0',c=getchar(); 7 k*=f; 8 } 9 const int maxn=6300*2; 10 int m,n,a,b,c,tot,s,t,last[maxn],to[maxn],nxt[maxn],del[maxn],dist[maxn],q[maxn]; 11 int main() 12 { 13 read(n);read(m);read(s);read(t); 14 for (register int i=1;i<=m;i++) 15 { 16 read(a);read(b);read(c); 17 nxt[++tot]=last[a]; 18 last[a]=tot; 19 to[tot]=b; 20 del[tot]=c; 21 nxt[++tot]=last[b]; 22 last[b]=tot; 23 to[tot]=a; 24 del[tot]=c; 25 } 26 for (register int i=1;i<=n;i++) 27 dist[i]=1<<30; 28 register int front=1,rear=1; 29 dist[s]=0; 30 q[1]=s; 31 while(front<=rear) 32 { 33 for (register int i=last[q[front]];i;i=nxt[i]) 34 if (dist[q[front]]+del[i]<dist[to[i]]) 35 { 36 dist[to[i]]=dist[q[front]]+del[i]; 37 q[++rear]=to[i]; 38 } 39 front++; 40 } 41 printf("%d\n",dist[t]); 42 }
1724: [Usaco2006 Nov]Fence Repair 切割木板
堆（同合并果子）
1 #include <cstdio> 2 #include <queue> 3 #define ll long long 4 std::priority_queue<int,std::vector<int>,std::greater<int> >q; 5 inline int read() 6 { 7 register int c=getchar(),f=1,k=0; 8 while (c<'0'||c>'9')c=='-'&&(f=-1),c=getchar(); 9 while (c>='0'&&c<='9')k=k*10+c-'0',c=getchar(); 10 return k*f; 11 } 12 const int maxn=20100; 13 long long n,a,ans; 14 int main() 15 { 16 n=read(); 17 register int a,b; 18 for (register int i=1;i<=n;i++) 19 a=read(),q.push(a); 20 for (register int i=1;i<n;i++) 21 { 22 a=q.top();q.pop(); 23 b=q.top();q.pop(); 24 ans+=a+b; 25 q.push(a+b); 26 } 27 printf("%lld\n",ans); 28 }
4094: [Usaco2013 Dec]Optimal Milking
线段树（维护4最值）
1 #include <cstdio> 2 #include <iostream> 3 using namespace std; 4 #define ll long long 5 inline int max(int a,int b) 6 { 7 return a>b?a:b; 8 } 9 inline int read() 10 { 11 register int c=getchar(),f=1,k=0; 12 while (c<'0'||c>'9')c=='-'&&(f=-1),c=getchar(); 13 while (c>='0'&&c<='9')k=k*10+c-'0',c=getchar(); 14 return k*f; 15 } 16 const int maxn=50000+100; 17 struct node{ 18 int l,r,clr,cl,cr,cnone; 19 }tree[maxn*8]; 20 ll ans; 21 int f[maxn],m,d,n,a[maxn],x,y; 22 inline void pushup(int x) 23 { 24 // 25 tree[x].clr=max(tree[x<<1].cl+tree[x<<1|1].cr,max(tree[x<<1].clr+tree[x<<1|1].cr,tree[x<<1].cl+tree[x<<1|1].clr)); 26 tree[x].cl=max(tree[x<<1].cl+tree[x<<1|1].cl,max(tree[x<<1].cl+tree[x<<1|1].cnone,tree[x<<1].clr+tree[x<<1|1].cnone)); 27 tree[x].cr=max(tree[x<<1].cr+tree[x<<1|1].cr,max(tree[x<<1].cnone+tree[x<<1|1].cr,tree[x<<1].cnone+tree[x<<1|1].clr)); 28 tree[x].cnone=max(tree[x<<1].cr+tree[x<<1|1].cnone,max(tree[x<<1].cnone+tree[x<<1|1].cl,tree[x<<1].cnone+tree[x<<1|1].cnone)); 29 30 } 31 void build(int l,int r,int cur) 32 { 33 tree[cur].l=l;tree[cur].r=r; 34 if (l==r) 35 { 36 tree[cur].clr=read(); 37 return; 38 } 39 register int mid=(l+r)>>1; 40 build(l,mid,cur<<1); 41 build(mid+1,r,cur<<1|1); 42 pushup(cur); 43 } 44 void update(int x,int y,int cur) 45 { 46 // cout << x<<" "<<y<< " "<<cur<<endl; 47 register int mid=(tree[cur].l+tree[cur].r)>>1; 48 if (tree[cur].l==x&&tree[cur].r==x){tree[cur].clr=y;return;}else if (x<=mid)update(x,y,cur<<1);else update(x,y,cur<<1|1); 49 pushup(cur); 50 } 51 int main() 52 { 53 n=read();d=read(); 54 build(1,n,1); 55 for (register int i=1;i<=d;i++) 56 { 57 x=read(),y=read(),update(x,y,1); 58 ans+=max(tree[1].clr,max(tree[1].cl,max(tree[1].cr,tree[1].cnone))); 59 } 60 printf("%lld\n",ans); 61 }
3407: [Usaco2009 Oct]Bessie's Weight Problem 贝茜的体重问题
背包
1 #include <cstdio> 2 inline int max(int a,int b) 3 { 4 return a>b?a:b; 5 } 6 inline int read() 7 { 8 register int f=1,c=getchar(),k=0; 9 while (c<'0'||c>'9')c=='-'&&(f=-1),c=getchar(); 10 while (c>='0'&&c<='9')k=k*10+c-'0',c=getchar(); 11 return k*f; 12 } 13 int d,f[45000*3],m; 14 int main() 15 { 16 d=read();m=read();register int cur; 17 for (register int i=1;i<=m;i++) 18 { 19 cur=read(); 20 for (register int j=d;j>=cur;j--) 21 f[j]=max(f[j],f[j-cur]+cur); 22 } 23 printf("%d\n",f[d]); 24 }
1012: [JSOI2008]最大数maxnumber
单标记线段树
1 #include <cstdio> 2 #define ll long long 3 inline int max(int a,int b) 4 { 5 return a>b?a:b; 6 } 7 inline int read() 8 { 9 register int f=1,c=getchar(),k=0; 10 while (c<'0'||c>'9')c=='-'&&(f=-1),c=getchar(); 11 while (c>='0'&&c<='9')k=k*10+c-'0',c=getchar(); 12 return k*f; 13 } 14 const int maxn=200010,inf=1<<30; 15 struct node{ 16 int l,r,delta; 17 }tree[maxn*16]; 18 int m,d,last,cu,tot; 19 void build(int l,int r,int cur) 20 { 21 tree[cur].l=l;tree[cur].r=r; 22 tree[cur].delta=-inf; 23 if (l==r)return; 24 register int mid=(l+r)>>1; 25 build(l,mid,cur<<1); 26 build(mid+1,r,cur<<1|1); 27 } 28 void update(int x,int c,int cur) 29 { 30 if (tree[cur].l==x&&tree[cur].r==x) 31 { 32 tree[cur].delta=c; 33 return; 34 } 35 register int mid=(tree[cur].l+tree[cur].r)>>1; 36 if (x<=mid)update(x,c,cur<<1);else update(x,c,cur<<1|1); 37 tree[cur].delta=max(tree[cur<<1|1].delta,tree[cur<<1].delta); 38 } 39 int query(int l,int r,int cur) 40 { 41 if (l<=tree[cur].l&&tree[cur].r<=r)return tree[cur].delta; 42 register int ans=-inf,mid=(tree[cur].l+tree[cur].r)>>1; 43 if (l<=mid)ans=query(l,r,cur<<1); 44 if (r>mid)ans=max(ans,query(l,r,cur<<1|1)); 45 return ans; 46 } 47 int main() 48 { 49 m=read();d=read(); 50 build(1,m,1); 51 for(register int i=1;i<=m;i++) 52 if (getchar()=='A')cu=read(),update(++tot,(last+cu)%d,1); 53 else cu=read(),printf("%d\n",last=query(tot-cu+1,tot,1)); 54 }
1370: [Baltic2003]Gang团伙
并查集
(题意贼坑：敌人的朋友不是敌人！！！）（坑我WA了4次QAQ
1 #include <cstdio> 2 #include <algorithm> 3 inline int read() 4 { 5 register int f=1,c=getchar(),k=0; 6 while (c<'0'||c>'9')c=='-'&&(f=-1),c=getchar(); 7 while (c>='0'&&c<='9')k=k*10+c-'0',c=getchar(); 8 return k*f; 9 } 10 const int maxn=5000*2+100; 11 int fa[maxn],n,m,a,b,be[maxn]; 12 int gf(int now) 13 { 14 return fa[now]==now?now:fa[now]=gf(fa[now]); 15 } 16 int main() 17 { 18 n=read();m=read(); 19 for (register int i=1;i<=(n<<1);i++)fa[i]=i; 20 register int ans=0; 21 for (register int i=1;i<=m;i++) 22 { 23 if (getchar()=='E')a=read(),b=read(),fa[gf(a)]=gf(b+n),fa[gf(b)]=gf(a+n); 24 else a=read(),b=read(),fa[gf(a)]=gf(b); 25 } 26 for (register int i=1;i<=n;i++) 27 be[i]=gf(i); 28 std::sort(be+1,be+1+n); 29 for (register int i=1;i<=n;i++) 30 if (be[i]!=be[i-1])ans++; 31 printf("%d\n",ans); 32 }
1572: [Usaco2009 Open]工作安排Job
堆+sort
View Code1726: [Usaco2006 Nov]Roadblocks第二短路
SPFA分类更新
1 #include <cstdio> 2 #include <queue> 3 #include <algorithm> 4 #define ll long long 5 using namespace std; 6 inline int min(int a,int b) 7 { 8 return a<b?a:b; 9 } 10 inline int read() 11 { 12 register int f=1,k=0;register char c=getchar(); 13 while (c<'0'||c>'9')c=='-'&&(f=-1),c=getchar(); 14 while (c>='0'&&c<='9')k=k*10+c-'0',c=getchar(); 15 return k*f; 16 } 17 const int maxn=101000*2,inf=1<<30; 18 struct edge{ 19 int x,too,nxt,co; 20 // bool operator<(const edge&a)const{return this->co>a.co;} 21 }e[maxn]; 22 int q[maxn]; 23 bool vis[maxn]; 24 int n,r,last[maxn],dist[maxn],dist2[maxn]; 25 //priority_queue<edge>q; 26 inline void spfa() 27 { 28 dist[1]=0; 29 register int h=0,t=1; 30 q[1]=1; 31 while (h!=t) 32 { 33 if (++h==maxn)h=0; 34 register int now=q[h]; 35 vis[now]=1; 36 for (register int i=last[now];i;i=e[i].nxt) 37 { 38 register bool flag=0;register int tmp=dist[now]+e[i].co; 39 if (tmp<dist[e[i].too]) 40 { 41 dist2[e[i].too]=min(dist[e[i].too],dist2[now]+e[i].co); 42 dist[e[i].too]=tmp; 43 flag=1; 44 } 45 else if (tmp>dist[e[i].too]&&tmp<dist2[e[i].too])dist2[e[i].too]=tmp,flag=1; 46 else if (tmp==dist[e[i].too]&&dist2[now]+e[i].co<dist2[e[i].too])dist2[e[i].too]=dist2[now]+e[i].co,flag=1; 47 if (flag&&(!vis[e[i].too])) 48 { 49 if (++t==maxn)t=0; 50 q[t]=e[i].too; 51 vis[e[i].too]=1; 52 } 53 } 54 vis[now]=0; 55 } 56 } 57 int main() 58 { 59 n=read();r=read(); 60 register int a,b,c; 61 for (register int i=1;i<=n;i++)dist[i]=dist2[i]=inf; 62 for (register int i=1;i<=r;i++) 63 { 64 65 a=read();b=read();c=read(); 66 e[i<<1].x=a; 67 e[i<<1].nxt=last[a]; 68 e[i<<1].too=b; 69 e[i<<1].co=c; 70 last[a]=i<<1; 71 e[i<<1|1].x=b; 72 e[i<<1|1].nxt=last[b]; 73 e[i<<1|1].too=a; 74 e[i<<1|1].co=c; 75 last[b]=i<<1|1; 76 } 77 spfa(); 78 printf("%d\n",dist2[n]); 79 }
4511: [Usaco2016 Jan]Subsequences Summing to Sevens
桶
1 #include <cstdio> 2 #define ll long long 3 inline ll read() 4 { 5 register int f=1,k=0;register char c=getchar(); 6 while (c<'0'||c>'9')c=='-'&&(f=-1),c=getchar(); 7 while (c>='0'&&c<='9')k=k*10+c-'0',c=getchar(); 8 return k*f; 9 } 10 inline ll max(ll a,ll b){return a>b?a:b;} 11 const int maxn=50010; 12 ll a[maxn],sum[maxn],t[10],ans; 13 int main() 14 { 15 register int n=read(); 16 for (register int i=1;i<=n;i++)a[i]=read(),sum[i]=(sum[i-1]+a[i])%7; 17 for (register int i=1;i<=n;i++)if (t[sum[i]])ans=max(i-t[sum[i]],ans);else t[sum[i]]=i; 18 printf("%lld\n",ans); 19 }
