poj-1088-滑雪【记忆化搜索+DP】

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#include<stdio.h>
#include<string.h>
int dp[110][110];
int a[110][110];
int max(int a,int b){
	return a>b?a:b;
}
int n,m;
int s[4][2]={1,0,0,1,-1,0,0,-1};
int dfs(int i,int j){
    if(dp[i][j]) return dp[i][j];
    for(int k=0;k<4;++k){
    	if(i+s[k][0]>0&&i+s[k][0]<=n&&j+s[k][1]>0&&j+s[k][1]<=m)
    	if(a[i][j]>a[i+s[k][0]][j+s[k][1]]){
    		dp[i][j]=max(dp[i][j],dfs(i+s[k][0],j+s[k][1])+1);
    	}
    }
    return dp[i][j];
}
int main(){
	while(~scanf("%d%d",&n,&m)){
		memset(dp,0,sizeof(dp));
		memset(a,0,sizeof(a));
		int i,j,res=0;
		for(i=1;i<=n;++i){
		   for(j=1;j<=m;++j){
			  scanf("%d",&a[i][j]);
		   }
		}
		for(i=1;i<=n;++i){
			for(j=1;j<=m;++j){
	                    res=max(res,dfs(i,j));
			}
		}
		printf("%d\n",res+1);
	}
	return 0;
}