简单题

#include 
      
       #include 
       
        using namespace std;#define maxn 50005int n;int f[maxn], g[maxn];int main(){    scanf("%d", &n);    if (n < 4)    {        puts("0");        return 0;    }    f[0] = 0;    for (int i = 1; i < n; i++)        scanf("%d", &f[i]);    for (int i = 1; i < n; i++)        g[i] = f[i] - f[i - 1];    int pos = min_element(g + 2, g + n - 1) - g;    printf("%d\n", f[n - 1] + g[pos]);    printf("%d %d %d 1\n", n, pos, pos + 1);    return 0;}