POJ1088 滑雪 DP+记忆化搜索

#include <cstdio>
#include <iostream>
#include <cstring>
using namespace std;
int map[105][105];
int dp[105][105];
int num,c,r;
int bfs(int x,int y)
{
    if(dp[x][y]) return dp[x][y];
    int nmax=1;
    int len;
    if(x+1<=r&&map[x][y]>map[x+1][y])
    {
        len=bfs(x+1,y)+1;
        if(len>nmax) nmax=len;
    }
    if(x-1>=1&&map[x][y]>map[x-1][y])
    {
        len=bfs(x-1,y)+1;
        if(len>nmax) nmax=len;
    }
    if(y+1<=c&&map[x][y]>map[x][y+1])
    {
        len=bfs(x,y+1)+1;
        if(len>nmax) nmax=len;
    }
    if(y-1>=1&&map[x][y]>map[x][y-1])
    {
        len=bfs(x,y-1)+1;
        if(len>nmax) nmax=len;
    }
    return dp[x][y]=nmax;
}
int main()
{
    int i,j;
    int nmax=0;
    scanf("%d%d",&r,&c);
    for(i=1;i<=r;i++)
      for(j=1;j<=c;j++)
        scanf("%d",&map[i][j]);
    memset(dp,0,sizeof(dp));
    for(i=1;i<=r;i++)
      for(j=1;j<=c;j++)
      {
          dp[i][j]=bfs(i,j);
          if(dp[i][j]>nmax) nmax=dp[i][j];
      }
    printf("%d\n",nmax);
    return 0;
}