題目鏈接

感謝 http://blog.csdn.net/txgang/article/details/77568491

#include<bits/stdc++.h>
using namespace std;

namespace FastIO
{
    const static int MX=1e6;
    bool IOerror=0;
    char nc()
    {
        static char buf[MX],*p1=buf+MX,*pend=buf+MX;
        if(p1==pend)
        {
            p1=buf;
            pend
 
=buf+fread(buf,1,MX,stdin);
            if(pend==p1)
            {
                IOerror=1;
                return -1;
            }
        }
        return *p1++;
    }
    inline bool blank(char ch)
    {
        return ch==‘ ‘||ch==‘\n‘||ch ==‘\r‘||ch ==‘\t‘;
    }
    inline int read()    //直接x=read()調用此函數即可，EOF會返回-1
 

    {
        int x;
        char ch;
        while(blank(ch=nc()));
        if(IOerror) return -1;
        for(x=ch-‘0‘;(ch=nc())>=‘0‘&&ch<=‘9‘;x=x*10+ch-‘0‘);//printf("%d===\n",x);
        return x;
    }
}
using namespace FastIO;

const int N=2e6+9;

int a[N],b[N];

int solve(int n)
{
    
 
for(int i=0;i<n;i++) a[i]=read(),a[i+n]=a[i];
    for(int i=0;i<n;i++) b[i]=read(),b[i+n]=b[i];
    int ret=0,fuck=0;
    int sum1=0,sum2=0,be=0;
    for(int i=0;i<2*n&&be<n;i++)
    {
        sum1+=a[i]+b[i];
        sum2+=a[i]-b[i];
        if(sum2<0||i-be+1==n)
        {
            if(sum1>fuck) ret=be,fuck=sum1;
            sum1=sum2=0;
            be=i+1;
        }
    }
    return ret;
}

int main()
{
//    freopen("test.in","r",stdin);
    int n;
    while((n=read())!=-1)
        printf("%d\n",solve(n));
}

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