50041. Mountains

#include <stdio.h>
#include <stdlib.h>

int main(){
    int n;
    long long ans = 0;
    int h1, h2, prev_height, prev_h, now_h;

    scanf("%d", &n);
    scanf("%d %d", &h1, &h2);
    prev_h = h2;
    prev_height = h2 - h1;
    if(prev_height > 0) ans += (3 * prev_height);
    if(prev_height < 0) ans += (-2 * prev_height);

    for(int i = 2; i < n; i++){
        scanf("%d", &now_h);
        int now_height = now_h - prev_h;
        if(now_height > 0){
            if(prev_height > 0) ans += (4 * now_height);
            else ans += (3 * now_height);
        }
        else{
            if(prev_height > 0) ans += (-3 * now_height);
            else ans += (-2 * now_height);
        }

        prev_h = now_h;
        prev_height = now_height;
    }
    printf("%lld\n", ans);
}