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题意：看后面也应该知道是什么意思了
解法：
我们设置l,r，符合条件就是l=起始点,r=当前点，不符合l=i+1
学习了一下FASTIO
  1 #include <iostream>
  2 #include <algorithm>
  3 #include <set>
  4 #include <string>
  5 #include <vector>
  6 #include <queue>
  7 #include <map>
  8 #include <stack>
  9 #include <list>
 10 #include <iomanip>
 11 #include <functional>
 12 #include <sstream>
 13 #include <cstdio>
 14 #include <cstring>
 15 #include <cmath>
 16 #include <cctype>
 17 //#define read read()
 18 #define edl putchar('
')
 19 #define ll long long
 20 #define clr(a,b) memset(a,b,sizeof a)
 21 #define rep(i,m,n) for(int i=m ; i<=n ; i++)
 22 #define fep(i,n) for(int i=0 ; i<n ; i++)
 23 //inline int read{ int x=0;char c=getchar();while(c<'0' || c>'9')c=getchar();while(c>='0' && c<='9'){ x=x*10+c-'0';c=getchar(); }return x;}
 24 
 25 namespace FastIO {
 26     const int SIZE = 1 << 16;
 27     char buf[SIZE], obuf[SIZE], str[60];
 28     int bi = SIZE, bn = SIZE, opt;
 29     int read(char *s) {
 30         while (bn) {
 31             for (; bi < bn && buf[bi] <= ' '; bi++);
 32             if (bi < bn) break;
 33             bn = fread(buf, 1, SIZE, stdin);
 34             bi = 0;
 35         }
 36         int sn = 0;
 37         while (bn) {
 38             for (; bi < bn && buf[bi] > ' '; bi++) s[sn++] = buf[bi];
 39             if (bi < bn) break;
 40             bn = fread(buf, 1, SIZE, stdin);
 41             bi = 0;
 42         }
 43         s[sn] = 0;
 44         return sn;
 45     }
 46     bool read(int& x) {
 47         int n = read(str), bf;
 48 
 49         if (!n) return 0;
 50         int i = 0; if (str[i] == '-') bf = -1, i++; else bf = 1;
 51         for (x = 0; i < n; i++) x = x * 10 + str[i] - '0';
 52         if (bf < 0) x = -x;
 53         return 1;
 54     }
 55 };
 56 #define read(x) FastIO::read(x)
 57 using namespace std;
 58 int X[1234567*2],Y[1234567*2];
 59 const int maxn = 1007;
 60 int n, m, mp[maxn][maxn], link[maxn];
 61 bool vis[maxn];
 62 int main() {
 63 
 64     while(read(n)) {
 65         for(int i=1;i<=n;i++){
 66             read(X[i]);
 67             X[n+i]=X[i];
 68         }
 69         for(int i=1;i<=n;i++){
 70             read(Y[i]);
 71             Y[i]=X[i]-Y[i];
 72             Y[i+n]=Y[i];
 73         }
 74         int sum=0;
 75         int ans=0;
 76         int index=1;
 77         int r=1;
 78         int St;
 79         int Max=-((1<<31)-1);
 80         for(int i=1;i<=2*n;i++){
 81             sum+=X[i];
 82             ans+=Y[i];
 83             if(sum>Max){
 84                 Max=sum;
 85                 St=index;
 86                 r=i;
 87             }
 88             if(ans<0){
 89                 index=i+1;
 90                 sum=0;
 91                 ans=0;
 92                 if(index>n+1){
 93                     break;
 94                 }
 95             }
 96         }
 97         printf("%d
",St-1);
 98     }
 99     return 0;
100 }