poj 1088 dp **

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记忆化搜索很好写

 #include<cstdio>
 #include<iostream>
 #include<algorithm>
 #include<cstring>
 #include<cmath>
 #include<queue>
 #include<map>
 using namespace std;
 #define MOD 1000000007
 const int INF=0x3f3f3f3f;
 const double eps=1e-;
 typedef long long ll;
 #define cl(a) memset(a,0,sizeof(a))
 #define ts printf("*****\n");
 const int MAXN=;
 int n,m,tt;
 int a[MAXN][MAXN];
 int dp[MAXN][MAXN];
 int d[][]={,,,,-,,,-};
 int fun(int x,int y)
 {
     if(dp[x][y]>)    return dp[x][y];
     dp[x][y]=;
     for(int i=;i<;i++)
     {
         int nx=x+d[i][];
         int ny=y+d[i][];
         if(nx>=&&nx<=n&&ny>=&&ny<=m&&a[x][y]>a[nx][ny])
         {
             if(dp[x][y]<fun(nx,ny)+)
                 dp[x][y]=dp[nx][ny]+;
         }
     }
     return dp[x][y];
 }
 int main()
 {
     int i,j,k;
     #ifndef ONLINE_JUDGE
     freopen("1.in","r",stdin);
     #endif
     while(scanf("%d%d",&n,&m)!=EOF)
     {
         for(i=;i<=n;i++)
         {
             for(j=;j<=m;j++)
             {
                 scanf("%d",&a[i][j]);
             }
         }
         memset(dp,-,sizeof(dp));
         int ans=;
         for(i=;i<=n;i++)
             for(j=;j<=m;j++)
             {
                 if(fun(i,j)>ans) ans=dp[i][j];
             }
         printf("%d\n",ans);
     }
 }