dfs(深度优先搜素)poj1088

#include<cstdio>
#include<iostream>
#include<algorithm>
using namespace std;
int dp[101][101],a[101][101];
int n,i,j,k,m;
int dfs(int x,int y){
if(dp[x][y]!=0) return dp[x][y];
if(x==0||x==n+1||y==0||y==m+1) return 0;
int maxn=0;
if(a[x-1][y]<a[x][y]) maxn=max(maxn,dfs(x-1,y));
if(a[x+1][y]<a[x][y]) maxn=max(maxn,dfs(x+1,y));
if(a[x][y-1]<a[x][y]) maxn=max(maxn,dfs(x,y-1));
if(a[x][y+1]<a[x][y]) maxn=max(maxn,dfs(x,y+1));
dp[x][y]=maxn+1;
return dp[x][y];
}
int main(){
while(cin>>n>>m){
memset(dp,0,sizeof(dp));
for(i=1;i<=n;i++)
for(j=1;j<=m;j++)
cin>>a[i][j];
for(i=1;i<=n;i++)
for(j=1;j<=m;j++)
dfs(i,j);
int ans=-1;
for(i=1;i<=n;i++)
for(j=1;j<=m;j++)
if(dp[i][j]>ans)
ans=dp[i][j];
cout<<ans<<endl;
}
return 0;
}