POJ 2128 Highways

Highways

原题：Highways
题意：高速公路上有n个站，n-1条单向路径，新来的市长希望加两条路满足任意两个城市都能相互到达，并使得距离最短
解法：看样例数据都看得出来，头尾延伸一条反向路，并使得两条路径重复覆盖的距离最小，即找一条最短的路

#include<iostream>
using namespace std;
int main(){
    int n;
    cin >> n;
    int f[50000], sum=0, min, k=1;
    for(int i = 0; i < n-1; i++){
        cin >> f[i];
    }
    for(int i = n-2; i > 0; i--){
        f[i]=f[i]-f[i-1];
    }
    for(int i = 0; i < n-1; i++) sum += f[i];
    min = 2*1e9;
    for(int i = 1; i < n-2; i++){
        if (f[i] < min){
            min=f[i];
            k=i;
        }
    }
    sum += min;
    if(n < 4){
        cout << "0" << endl;
    } else {
        cout << sum << endl;
        cout << k+2 << " " << "1" << " " << n << " " << k+1 << endl;
    }
}