Acwing 901. 滑雪

Acwing 901. 滑雪

思路：

代码：

#include<iostream>
#include<cstring>
using namespace std;
const int N = 305;
int n, m;
int g[N][N], f[N][N];

int dx[4] = {0, -1, 0, 1}, dy[4] = {1, 0, -1, 0};

int dp(int x,int y){
    if(f[x][y] != -1) return f[x][y];
    
    int &v = f[x][y];
    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 && g[a][b] < g[x][y]){
            v = max(v, dp(a, b) + 1);
        }
    }
    return f[x][y];
}

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 >> g[i][j];
        }
    }
    int ans = 0;
    for(int i = 1; i <= n; i++){
        for(int j = 1; j <= m; j++){
            ans = max(ans, dp(i , j));
        }
    }
    cout << ans;
    return 0;
}