HDU 4221 Greedy?（贪心）

题意：

思路：

 

#include<cstdio>

#include<iostream>

#include<cstring>

#include<cmath>

#include<stdlib.h>

#include<vector>

#include<queue>

#include<stack>

#include<algorithm>

using namespace std;

struct Work

{

    __int64 c,d;

};

Work work[100000+10];

int cmp(Work a,Work b)

{

    if(a.d==b.d)

    {

        return a.c<b.c;

    }

    return a.d<b.d;

}

int main()

{

    __int64 time ,ans;

    int cas=1;

    int t,n;

    int i,j,k;

    scanf("%d",&t);

    while(t--)

    {

        ans=0;time=0;

        scanf("%d",&n);

        for(i=0;i<n;i++)

        {

            scanf("%I64d%I64d",&work[i].c,&work[i].d);

        }

        sort(work,work+n,cmp);

        for(i=0;i<n;i++)

        {

            time+=work[i].c;

            if(time>work[i].d&&ans<time-work[i].d)

            {

                ans=time-work[i].d;

            }

        }

        printf("Case %d: %I64d\n",cas++,ans);

    }

    return 0;

}