The task is really simple: given N exits on a highway which forms a simple cycle, you are supposed to tell the shortest distance between any pair of exits.
Input Specification:
Each input file contains one test case. For each case, the first line contains an integer N (in [3,105]), followed by N integer distances D1 D2 ⋯ DN, where Di is the distance between the i-th and the (i+1)-st exits, and DNis between the N-th and the 1st exits. All the numbers in a line are separated by a space. The second line gives a positive integer M (≤104), with M lines follow, each contains a pair of exit numbers, provided that the exits are numbered from 1 to N. It is guaranteed that the total round trip distance is no more than 107.
Output Specification:
For each test case, print your results in M lines, each contains the shortest distance between the corresponding given pair of exits.
Sample Input:
5 1 2 4 14 9 3 1 3 2 5 4 1
Sample Output:
3 10 7
#include<iostream>
#include<vector>
using namespace std;
int main()
{
int n;
cin>>n;
vector<int>dis(n+1);
int sum=0,left,right,cnt;
for(int i=1;i<=n;i++)
{
int temp;
cin>>temp;
sum+=temp;
dis[i]=sum;///存储距离和
}
///dis[0]=0,dis[1]=1,dis[2]=3,dis[3]=7,dis[4]=21,dis[5]=30;
cin>>cnt;
for(int i=0;i<cnt;i++)
{
cin>>left>>right;
if(left>right)
swap(left,right);///始终保持左边小于右边
int temp=dis[right-1]-dis[left-1];///求差值
cout<<min(temp,sum-temp)<<endl;///正反对比找最小
}
}
/// 1-(1)-2-(2)-3-(4)-4-(14)-5-
/// | |
/// |---------(9)-------------|