#6 AC，模拟算法，自测样例可过

思路：寻找每个坑，看看可不可以容纳水

大佬求救！

#include<bits/stdc++.h>
#define int long long
using namespace std;
int a[10005];
signed main(){
    ios::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
	int n; cin >> n;
	for(int i = 1;i <= n;i++) cin >> a[i];
	int ans = 0;
    for(int i = 2;i <= n;i++){
        if(a[i] < a[i - 1]){
            int j = i + 1;
            while(a[j] < a[i - 1] && j <= n) j++;
            int minn = 5001;
            for(int l = i;l < j;l++) minn = min(minn,min(a[i - 1],a[j]) - a[l]);
            ans += minn * (j - i);
        }
        //cout << ans << " ";
    }
    cout << ans << " ";
    return 0;
}