leecode动态规划滑雪

１．滑雪

//https://blog.youkuaiyun.com/qq_25202231/article/details/72925477
// dp( i,j ) = Max( dp( i-1, j ), dp( i, j+1 ),dp( i+1, j ), dp( i, j-1 ) ) + 1;


#include <iostream>  
#include <fstream>  
#include <algorithm>  
using namespace std;  
  
int map[105][105], dp[105][105];  
int n, m;  
int solve(int x, int y)  
{  
    if (dp[x][y])  
        return dp[x][y];  
    int MAX = 1;  
    int cur_height = map[x][y];  
    if (x + 1 <= n&&cur_height > map[x + 1][y])  
    {  
        int tmp = solve(x + 1, y) + 1;  
        MAX = max(MAX, tmp);  
    }  
    if (x - 1 > 0&&cur_height > map[x - 1][y])  
    {  
        int tmp = solve(x - 1, y) + 1;  
        MAX = max(MAX, tmp);  
    }  
    if (y + 1 <= m&&cur_height > map[x][y + 1])  
    {  
        int tmp = solve(x, y + 1) + 1;  
        MAX = max(MAX, tmp);  
    }  
    if (y - 1 > 0&&cur_height > map[x][y - 1])  
    {  
        int tmp = solve(x, y - 1) + 1;  
        MAX = max(MAX, tmp);  
    }  
    dp[x][y] = MAX;  
    return MAX;  
}  
  
int main()  
{  
    //fstream cin("test.txt");  
    cin >> n >> m;  
    for (int i = 1; i <= n; i++)  
        for (int j = 1; j <= m; j++)  
            cin >> map[i][j];  
    for (int i = 1; i <= n; i++)  
        for (int j = 1; j <= m; j++)  
            solve(i, j);  
    int ans = 1;  
    for (int i = 1; i <= n; i++)  
        for (int j = 1; j <= m; j++)  
            ans = max(ans, dp[i][j]);  
    cout << ans << endl;  
    //system("pause");  
    return 0;  
}