【Codeforces Round #693 (Div. 3) C】Long Jumps

题目链接

链接

翻译

translation

题解

动规。

(f[i] = f[i+a[i]]+a[i]) 类似这样?...倒着推一下，注意边界就行。

代码

#include <bits/stdc++.h>
#define lson l,mid,rt*2
#define rson mid+1,r,rt*2+1
#define LL long long
using namespace std;

const int N = 2e5;

int n;
int a[N+10];
LL f[N+10];

int main(){
    ios::sync_with_stdio(0),cin.tie(0);
    int T;
    cin >> T;
    while (T--){
        cin >> n;
        for (int i = 1;i <= n; i++){
            cin >> a[i];
        }
        LL ans = 0;
        for (int i = n;i >= 1;i--){
            int j = i+a[i];
            if (j > n){
                f[i] = a[i];
            }else{
                f[i] = a[i]+f[j];
            }
            ans = max(ans,f[i]);
        }
        cout << ans << endl;
    }
    return 0;
}