Submission

Score: 100

User: erng

Problemset: อัศวินขี่ม้าขาว

Language: cpp

Time: 0.136 second

Submitted On: 2026-03-05 08:04:41

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

#define ll long long

const ll nx=1005;

ll n, m, mp[nx][nx], l, r, md, dp[nx][nx], k;

int main()
{
    cin.tie(NULL)->sync_with_stdio(false);
    cin>>n>>m;
    for (int i=1; i<=n; i++)
    {
        for (int j=1; j<=m; j++)
        {
            cin>>mp[i][j];
        }
    }
    l=1;
    r=1e15;
    while (l<r)
    {
        md=l+(r-l)/2;
        dp[1][1]=md+mp[1][1];
        if (dp[1][1]<=0) dp[1][1]=-1e15;
        for (int i=1; i<=n; i++)
        {
            for (int j=1; j<=m; j++)
            {
                if (i==1 && j==1) continue;
                dp[i][j]=-1e15;
                if (j>1) dp[i][j]=max(dp[i][j], dp[i][j-1]+mp[i][j]);
                if (i>1) dp[i][j]=max(dp[i][j], dp[i-1][j]+mp[i][j]);
                if (dp[i][j]<=0) dp[i][j]=-1e15;
            }
        }
        if (dp[n][m]<=0)
        {
            l=md+1;
        }
        else
        {
            r=md;
        }
    }
    cout<<r;
}