hdu 4296

//贪心，按w+s排序;

//证明详见：http://www.cnblogs.com/liulangye/archive/2012/09/17/2689062.html 

//代码如下：

 

#include<stdio.h>#include<algorithm>using namespace std;struct node{    int w,s;}num[110000];bool cmp(node a,node b){    return (a.w+a.s)<(b.w+b.s);}int main(){    int n,i;    __int64 Max,sum,tt;    while(scanf("%d",&n)!=EOF)    {        for(i=0;i<n;i++)            scanf("%d%d",&num[i].w,&num[i].s);        sort(num,num+n,cmp);        Max=0;        sum=num[0].w;        for(i=1;i<n;i++)        {            tt=sum-num[i].s;            if(tt>Max)                Max=tt;            sum+=num[i].w;        }        printf("%I64d\n",Max);    }    return 0;}