QBMAX.cpp

#include <bits/stdc++.h>
using namespace std;

typedef long long ll;

int main() {
    int n, m;
    cin >> n >> m;
    vector<vector<int>> a(n + 2, vector<int>(m + 1));
    for (int i = 1; i <= n; i++)
    for (int j = 1; j <= m; j++) {
        cin >> a[i][j];
    }
    vector<vector<int>> dp(n + 2, vector<int>(m + 1, -1e4));
    int ans = -1e4;
    for (int j = 1; j <= m; j++)
    for (int i = 1; i <= n; i++) {
        if (j == 1) dp[i][1] = a[i][1];
        else dp[i][j] = a[i][j] + max({dp[i - 1][j - 1], dp[i][j - 1], dp[i + 1][j - 1]});
        if (j == m) ans = max(ans, dp[i][j]);
    }
    cout << ans << '\n';
}