70分求调 谢谢

#include<bits/stdc++.h>
using namespace std;
const int N = 1e3+1;
int mp[N][N];
int n,m;
int h[N][N];
int all;
bool jud(int x,int y)
{
    return 
    (!h[x][y+1]||h[x][y+1]>=h[x][y])&&
    (!h[x][y-1]||h[x][y-1]>=h[x][y])&&
    (!h[x+1][y]||h[x+1][y]>=h[x][y])&&
    (!h[x-1][y]||h[x-1][y]>=h[x][y]);
}
void dfs(int x,int y,int a,int b,int ans)
{
    if(mp[x][y])
    {
        ans+=mp[x][y];
        mp[a][b]=max(mp[a][b],ans);
        return;
    }
    ans++;
    if(jud(x,y))
    {
        mp[a][b]=max(mp[a][b],ans);
        return;
    }
    if(h[x][y+1]&&h[x][y+1]<h[x][y])dfs(x,y+1,a,b,ans);
    if(h[x][y-1]&&h[x][y-1]<h[x][y])dfs(x,y-1,a,b,ans);
    if(h[x+1][y]&&h[x+1][y]<h[x][y])dfs(x+1,y,a,b,ans);
    if(h[x-1][y]&&h[x-1][y]<h[x][y])dfs(x-1,y,a,b,ans);
    return;
}

int main()
{
    memset(mp,0,sizeof(mp));
    cin>>m>>n;
    for(int i=1;i<=n;i++)
    {
        for(int j=1;j<=m;j++)
        {
            cin>>h[i][j];
        }
    }
    for(int i=1;i<=n;i++)
    {
        for(int j=1;j<=m;j++)
        {
            dfs(i,j,i,j,0);
        }
    }
    for(int i=1;i<=n;i++)
    {
        for(int j=1;j<=m;j++)
        {
            //cout<<mp[i][j]<<" ";
            all=max(all,mp[i][j]);
        }
        //cout<<endl;
    }
    cout<<all;
}