1046. Shortest Distance (20) PAT 甲级

Problem Description

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 DN is 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

传送门

#include<iostream>#include<algorithm>using namespace std;#define MAX_N 100005int dis[MAX_N];int A[MAX_N];int main(){    int sum=0;    int N;    int M;    int left,right;    int temp;    cin>>N;    for(int i=1;i<=N;i++){        cin>>A[i];        sum+=A[i];        dis[i]=sum;    }    cin>>M;    for(int i=0;i<M;i++){        cin>>left>>right;        if(left>right){            temp=left;            left=right;            right=temp;        }        temp=dis[right-1]-dis[left-1];        cout<<min(temp,sum-temp)<<endl;    }}