1046 Shortest Distance (20分)

先把距离算出来，用数组存储起来，否则每次查询都就要重新算一次，导致超时。

#include <iostream>
using namespace std;
int main()
{
    int n;     cin >> n;
    int sum = 0;
    unsigned long int* d = new unsigned long int[n];
    unsigned long int * dst = new unsigned long int[n];
    for (int i = 0; i < n; i++)
    {
        dst[i] = sum;//顺时针方向各点到第一个点的距离
        cin >> d[i];
        sum += d[i];
    }
    int k; cin >> k;
    for (int i = 0; i < k; i++)
    {
        int n1, n2, res1 = 0, res2 = 0;
        cin >> n1 >> n2;
        res1 = n1<n2?dst[n2 - 1] - dst[n1 - 1]:dst[n1-1]-dst[n2-1];
        cout << (sum-res1 < res1 ? sum-res1 : res1);
        if (i != k - 1)cout << endl;
    }
    return 0;
}