Day2代码

#include<cstdio>
#include<cstring>
#include<cmath>
#include<algorithm>
#define lli long long int 
using namespace std;
const lli MAXN=401;
const lli INF=0x7ffff;
inline void read(lli &n)
{
    char c=getchar();n=0;bool flag=0;
    while(c<'0'||c>'9')    c=='-'?flag=1,c=getchar():c=getchar();
    while(c>='0'&&c<='9')    n=n*10+c-48,c=getchar();n=flag==1?-n:n;
}
lli n,m,s,k;
struct C
{
    lli ID;
    lli score;
}sj[MAXN];
bool how[MAXN];
lli ans=-1;
lli impro[MAXN];
lli comp(const C &a,const C &b)
{
    return a.score<b.score;
}
lli now=0;
void pd()
{
    memset(impro,0,sizeof(impro));
    for(lli i=1;i<=m;i++)
        if(how[i])
            impro[sj[i].ID]+=(-sj[i].score);
    for(lli i=1;i<=n;i++)
        if(impro[i]<k)
            return ;
    lli cur=0;
    for(lli i=1;i<=n;i++)
        cur+=impro[i];
    ans=max(ans,cur);
}
void dfs(lli now,lli spend)
{
    if(now==m+1)    {    pd();    return ;    }
    if(spend<s)
    {
        how[now]=1;
        dfs(now+1,spend+1);// tou
        how[now]=0;    
    }
    how[now]=0;
    dfs(now+1,spend);//bu tou 
}
void check()
{
    ans=0;
    for(lli i=1;i<=m;i++)
    {
        if(impro[sj[i].ID]<k&&sj[i].score<0)
            if(now<s)
            {    impro[sj[i].ID]+=(-sj[i].score);    now++;    
                ans+=(-sj[i].score);    sj[i].score=INF;     }    
            else
            {    printf("-23333333");    exit(0);    }
        else    continue;
    }
    for(lli i=1;i<=n;i++)
        if(impro[i]<k)
            {    printf("-23333333");    exit(0);    }

    sort(sj+1,sj+m+1,comp);
    for(lli i=1;i<=m;i++)
        if(now<s&&sj[i].score!=INF&&sj[i].score<0)
            ans+=(-sj[i].score),    now++;
    printf("%lld",ans);
}
int main()
{
    freopen("express.in","r",stdin);
    freopen("express.out","w",stdout);
    read(n);read(m);read(s);read(k);
    for(lli i=1;i<=m;i++)
    {
        read(sj[i].ID);read(sj[i].score);
        sj[i].score=2-sj[i].score;
    }
    if(n<=20)
    {
        dfs(0,0);
        if(ans==-1)    printf("-23333333");
        else printf("%lld",ans);    
    }
    else
    {
        sort(sj+1,sj+m+1,comp);
        check();
    }
    return 0;
}

#include<iostream>
#include<cstdio>
#include<cstring>
#include<cmath>
#include<algorithm>
using namespace std;
const int MAXN=401;
inline void read(int &n)
{
    char c=getchar();n=0;bool flag=0;
    while(c<'0'||c>'9')    c=='-'?flag=1,c=getchar():c=getchar();
    while(c>='0'&&c<='9')    n=n*10+c-48,c=getchar();n=flag==1?-n:n;
}
string a;
void work(int bg,int ed)
{
    string b;    int now=0;
    for(int i=ed-1;i>bg;i--)    
        if(a[i]=='(')    b=b+')';
        else if(a[i]==')')    b=b+'(';
        else b=b+a[i];
    for(int i=bg+1;i<ed;i++)    a[i]=b[now++];    a[bg]='$';a[ed]='$';
}
int main()
{
    freopen("unknown.in","r",stdin);
    freopen("unknown.out","w",stdout);
    cin>>a;
    int la=a.length();
    int now=0;
    int bg=0,ed=0;
    while(a.find('(')!=a.npos)
    {
        for(int i=0;i<a.length();i++)
        {
            if(a[i]=='(')    {    if(now==0)    bg=i;                now++;    }
            if(a[i]==')')    {    if(now==1)    ed=i,work(bg,ed);    now--;    }
        }    
    //    cout<<a<<endl;
    }
    for(int i=0;i<=a.length();i++)
        if(a[i]!='$')    cout<<a[i];
    return 0;
}

#include<cstdio>
#include<cstring>
#include<cmath>
#include<algorithm>
using namespace std;
const int MAXN=438; 
const int INF=100001;
inline void read(int &n)
{
    char c=getchar();n=0;bool flag=0;
    while(c<'0'||c>'9')    c=='-'?flag=1,c=getchar():c=getchar();
    while(c>='0'&&c<='9')    n=n*10+c-48,c=getchar();n=flag==1?-n:n;
}
int map[438][438];
int n,m,k;
int main()
{
    freopen("prison.in","r",stdin);
    freopen("prison.out","w",stdout);
    read(n);read(m);read(k);
    for(int i=1;i<=m;i++)
    {
        int x,y;read(x);read(y);
        map[x][y]=1;map[y][x]=1;
    }
    if(n==2)
    {
        if(map[1][2])
        {
            if(k==0)    printf("2");
            else printf("1");
        }
        else printf("1");
    }
    else
    {
        printf("%d",rand()%n);
    }
    return 0;
}