HDU 1422 重温世界杯(最长正子段长度)

////  main.cpp//  Richard////  Created by 邵金杰 on 16/9/25.//  Copyright © 2016年 邵金杰. All rights reserved.//#include<iostream>#include<cstdio>#include<cstring>#include<algorithm>using namespace std;const int maxn=100000+100;int a[maxn*2],dp[maxn*2];int main(){    int n;    while(scanf("%d",&n)!=EOF)    {        memset(dp,0,sizeof(dp));        int u,v;        int ans=0;        for(int i=1;i<=n;i++){scanf("%d%d",&u,&v);a[i]=a[i+n]=u-v;}        int sum=0;        for(int i=1;i<=2*n;i++)        {            sum+=a[i];            if(sum>=0) dp[i]=dp[i-1]+1;            else sum=0;            ans=max(ans,dp[i]);            if(ans==n) break;        }        cout<<ans<<endl;    }    return 0;}