1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39

#include <iostream>
#include <vector>
#include <algorithm>
#include <cmath>

class Solution {
public:
    int maxCollectedFruits(std::vector<std::vector<int>>& fruits) {
        int n = fruits.size();
        int sum = 0;
        for (int i = 0; i < n; ++i) {
            sum += fruits[i][i];
            fruits[i][i] = 0;
        }
        
        std::vector<int> dp(n + 2, 0x8000'0000);
        std::vector<int> tmp(n + 2);
        dp[n] = fruits[0].back();
        for (int i = 1; i < n; ++i) {
            std::swap(dp, tmp);
            for (int j = 1; j <= n; ++j) {
                dp[j] = std::max(std::max(tmp[j - 1], tmp[j]), tmp[j + 1]) + fruits[i][j - 1];
            }
        }
        sum += dp[n];
        
        std::fill(dp.begin(), dp.end(), 0x8000'0000);
        dp[n] = fruits.back()[0];
        for (int i = 1; i < n; ++i) {
            std::swap(dp, tmp);
            for (int j = 1; j <= n; ++j) {
                dp[j] = std::max(std::max(tmp[j - 1], tmp[j]), tmp[j + 1]) + fruits[j - 1][i];
            }
        }
        sum += dp[n];
        
        return sum;
    }
};