PAT 甲级 1046 Shortest Distance
https://pintia.cn/problem-sets/994805342720868352/problems/994805435700199424
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, 10^5^]), followed by N integer distances D~1~ D~2~ ... D~N~, where D~i~ is the distance between the i-th and the (i+1)-st exits, and D~N~ 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 (<=10^4^), 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 10^7^.
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
代码:
#include <bits/stdc++.h> using namespace std; const int maxn = 1e5 + 10; int a[maxn], dis[maxn]; int main() { int N, sum = 0; scanf("%d", &N); for(int i = 1; i <= N; i ++) { scanf("%d", &a[i]); sum += a[i]; dis[i] = sum; } int T, left, right, temp; scanf("%d", &T); for(int i = 1; i <= T; i ++) { scanf("%d%d", &left, &right); if(left > right) { swap(left, right); } temp = dis[right - 1] - dis[left - 1]; printf("%d\n", min(temp, sum - temp)); } return 0; }