A38783.元素距离积（简单）

题解来咯

#include<stdio.h>
#include<math.h>
int calculate_sum(int* A,int N){
    int total = 0;
    for (int d=1;d<N;d++)
        for (int j=0;j<N-d;j++)
            total += d * fabs(A[j] - A[j + d]);
    return total * 2;
}
int main(){
    int n;
    int a[110];
    scanf("%d",&n);
    for (int i=0;i<n;i++){
        scanf("%d",&a[i]);
    }
    printf("%d",calculate_sum(a,n));
    return 0;
}