The 2018 ACM-ICPC Chinese Collegiate Programming Contest Fight Against Monsters

 #include <iostream>
 #include <cstdio>
 #include <cstring>
 #include <string>
 #include <algorithm>
 #include <utility>
 #include <vector>
 #include <map>
 #include <queue>
 #include <stack>
 #include <cstdlib>
 typedef long long ll;
 #define lowbit(x) (x&(-x))
 #define ls l,m,rt<<1
 #define rs m+1,r,rt<<1|1
 using namespace std;
 int t,n;
 const int  N=1e5+;
 struct Node{
     int h;
     ll w;
     int f;
 }node[N];
 bool cmp(Node x,Node y){
     double xx=1.0*x.f/x.w;
     double yy=1.0*y.f/y.w;
     return xx<yy;
 }
 /*
 最好是先攻击 ：被攻击次数越少，并且伤害力又大
 也即是按照
 需要被攻击的次数/伤害力
 由小到大排序
 */
 int  main()
 {
     scanf("%d",&t);
     for(int i=;i<=t;i++)
     {  memset(node,,sizeof(node));
         scanf("%d",&n);
          ll sum=;
         for(int i=;i<n;i++){
             scanf("%d%lld",&node[i].h,&node[i].w);
             sum+=node[i].w;
         }
         int k,ans;
         for(int i=;i<n;i++)
         {   k=;
             ans=;
             while(node[i].h>){
                 node[i].h-=k;
                 k++;
                 ans++;
             }
             node[i].f=ans;
         }
         sort(node,node+n,cmp);
         ll ret=;
         for(int i=;i<n;i++)

             {
                 node[i].f=node[i-].f+node[i].f;
             }
         for(int i=;i<n;i++)
         {
             ret+=node[i].f*node[i].w;
         }
         printf("Case #%d: %lld\n",i,ret);
     }
     return ;
 }