题目链接：滑雪

#include <cstring>
#include <algorithm>
#include <iostream>using namespace std;const int N = 310;int n, m;
int h[N][N];
int f[N][N];int dx[4] = {-1, 0, 1, 0}, dy[4] = {0, 1, 0, -1};int dp(int x, int y)
{int &v = f[x][y];if(v != -1) return v;v = 1;for(int i = 0; i < 4; i ++){int a = x + dx[i], b = y + dy[i];if(a >= 1 && a <= n && b >= 1 && b <= m && h[a][b] < h[x][y])v = max(v, dp(a, b) + 1);}return v;
}int main()
{cin >> n >> m;memset(f, -1, sizeof f);for(int i = 1; i <= n; i ++)for(int j = 1; j <= m; j ++)cin >> h[i][j];int res = 0;for(int i = 1; i <= n; i ++)for(int j = 1; j <= m; j ++)res = max(res, dp(i, j));cout << res << endl;return 0;
}