#include <bits/stdc++.h>
using namespace std;
int r,c,a[105][105],f[105][105],ans;//f[i][j]代表第i行第j列的最长题意长度 
int main()
{
	cin >>r >> c;
	for (int i=1; i <=r; i++)
	{
		for (int j = 1; j <= c; j++)
		{
			cin >> a[i][j];
		}
	}
	for (int i = 1; i <= r; i++)
	{
		for (int j = 1; j <= c; j++)
		{
			f[i][j]=1;//初始每个点都可以滑雪，赋值1
		}
	}
	for (int i = 1; i <= r; i++)
	{
		for (int j = 1; j <= c; j++)
		{
			if (i+1<=r&&a[i][j]>a[i+1][j])
			{
				f[i][j]=max(f[i][j],f[i+1][j]);
			}
			if (i-1>0&&a[i][j]>a[i-1][j])
			{
				f[i][j]=max(f[i][j],f[i-1][j]);
			}
			if (j+1<=c&&a[i][j]>a[i][j+1])
			{
				f[i][j]=max(f[i][j],f[i][j+1]);
			}
			if (j-1>0&&a[i][j]>a[i][j-1])
			{
				f[i][j]=max(f[i][j],f[i][j-1]);
			}
			++f[i][j];
			ans=max(ans,f[i][j]);
		}
	}
	cout << ans;
}

十分感谢！