POJ1088 滑雪 | UVa10285 - Longest Run on a Snowboard

POJ1088 滑雪：http://poj.org/problem?id=1088

Tags: mDFS(记忆化搜索)

Code:

#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>
using namespace std;

const int maxn = 110;

int dx[] = {1,-1,0,0};
int dy[] = {0,0,1,-1};
int h[maxn][maxn];
int dp[maxn][maxn];
int R, C;
int DP(int x, int y)
{
     int i, xx, yy;
     if(dp[x][y]!=-1) return dp[x][y];
     int ans = 0;
     for(i=0; i<4; i++) {
          xx = x+dx[i];
          yy = y+dy[i];
          if(xx<0||xx>=R||yy<0||yy>=C||h[x][y]<=h[xx][yy]) continue;
          ans = max(ans, DP(xx,yy) );
     }
     return dp[x][y] = ans + 1;
}
int main()
{
     int i, j, ans, tmp;
     while(cin>>R>>C) {
          ans = 0;
          for(i=0; i<R; i++)
               for(j=0; j<C; j++) {
                    cin>>h[i][j];
               }
          memset(dp,-1,sizeof(dp));
          for(i=0; i<R; i++)
               for(j=0; j<C; j++) {
                    tmp = DP(i,j);
                    ans = max(ans,tmp);
               }
          cout<<ans<<endl;
     }
     return 0;
}