HDU5163Taking Bus（水题）

用画图工具画画线段就能明显看出来

#include<cstdio>#include<stack>#include<cstring>#include<algorithm>#include<iostream>#include<math.h>using namespace std;__int64 shu[100010];int main(){     // freopen("G://test.txt","r",stdin);    int t;    int n,m;   scanf("%d",&t);   while(t--){    scanf("%d%d",&n,&m);    shu[0]=0;    for(int i=1;i<n;++i){    scanf("%I64d",&shu[i]);    shu[i]=shu[i-1]+shu[i];    }    for(int i=0;i<m;++i){        int x;        int y;        scanf("%d %d",&x,&y);        __int64 sum=0;        int now=(i)%n+1;        if(y>x){        if(now>x){        sum=shu[n-1]-shu[now-1]+shu[n-1]+shu[y-1];        }        else{        sum=shu[y-1]-shu[now-1];        }        }        else{        sum=shu[n-1]-shu[now-1]+shu[n-1]-shu[y-1];        }        printf("%I64d\n",sum);    }       }     return 0;}