Day2代码

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

     sort(sj+,sj+m+,comp);
     for(lli i=;i<=m;i++)
         if(now<s&&sj[i].score!=INF&&sj[i].score<)
             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=;i<=m;i++)
     {
         read(sj[i].ID);read(sj[i].score);
         sj[i].score=-sj[i].score;
     }
     if(n<=)
     {
         dfs(,);
         if(ans==-)    printf("-23333333");
         else printf("%lld",ans);
     }
     else
     {
         sort(sj+,sj+m+,comp);
         check();
     }
     return ;
 }

 #include<iostream>
 #include<cstdio>
 #include<cstring>
 #include<cmath>
 #include<algorithm>
 using namespace std;
 const int MAXN=;
 inline void read(int &n)
 {
     char c=getchar();n=;bool flag=;
     while(c<''||c>'')    c=='-'?flag=,c=getchar():c=getchar();
     while(c>=''&&c<='')    n=n*+c-,c=getchar();n=flag==?-n:n;
 }
 string a;
 void work(int bg,int ed)
 {
     string b;    int now=;
     for(int i=ed-;i>bg;i--)
         if(a[i]=='(')    b=b+')';
         else if(a[i]==')')    b=b+'(';
         else b=b+a[i];
     for(int i=bg+;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=;
     int bg=,ed=;
     while(a.find('(')!=a.npos)
     {
         for(int i=;i<a.length();i++)
         {
             if(a[i]=='(')    {    if(now==)    bg=i;                now++;    }
             if(a[i]==')')    {    if(now==)    ed=i,work(bg,ed);    now--;    }
         }
     //    cout<<a<<endl;
     }
     for(int i=;i<=a.length();i++)
         if(a[i]!='$')    cout<<a[i];
     return ;
 }

 #include<cstdio>
 #include<cstring>
 #include<cmath>
 #include<algorithm>
 using namespace std;
 const int MAXN=;
 const int INF=;
 inline void read(int &n)
 {
     char c=getchar();n=;bool flag=;
     while(c<''||c>'')    c=='-'?flag=,c=getchar():c=getchar();
     while(c>=''&&c<='')    n=n*+c-,c=getchar();n=flag==?-n:n;
 }
 int map[][];
 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=;i<=m;i++)
     {
         int x,y;read(x);read(y);
         map[x][y]=;map[y][x]=;
     }
     if(n==)
     {
         if(map[][])
         {
             if(k==)    printf("");
             else printf("");
         }
         else printf("");
     }
     else
     {
         printf("%d",rand()%n);
     }
     return ;
 }