hdu1078 dfs+dp（记忆化搜索）搜索一条递增路径，路径和最大，起点是（0,0）

 #include<bits/stdc++.h>
 using namespace std;
 typedef unsigned int ui;
 typedef long long ll;
 typedef unsigned long long ull;
 #define pf printf
 #define prime1 1e9+7
 #define prime2 1e9+9
 #define scand(x) scanf("%llf",&x)
 #define f(i,a,b) for(int i=a;i<=b;i++)
 #define scan(a) scanf("%d",&a)
 #define dbg(args) cout<<#args<<":"<<args<<endl;
 #define pb(i) push_back(i)
 #define ppb(x) pop_back(x)
 #define maxn 1005
 int n,k,t;
 int Map[maxn][maxn],dp[maxn][maxn];
 int dir[][]={{,},{,-},{-,},{,}};
 bool ok(int x,int y)
 {
     if(x<||x>=n||y<||y>=n)return false;
     return true;
 }
 int dfs(int x,int y)
 {
     if(dp[x][y])return dp[x][y];
     int temp=;
     int M=;
     f(i,,)
         f(j,,k)
         {
             int xx=x+dir[i][]*j;
             int yy=y+dir[i][]*j;
             if(ok(xx,yy)&&Map[xx][yy]>Map[x][y])
             {
                 temp=dfs(xx,yy);
                 if(temp>dp[xx][yy])dp[xx][yy]=temp;
                 if(dp[xx][yy]>M)M=dp[xx][yy];
             }
         }

     return dp[x][y]=Map[x][y]+M;
 }
 int main()
 {
     std::ios::sync_with_stdio(false);
     while(scanf("%d%d",&n,&k)==&&!(k==-&&n==-))
     {
         memset(dp,,sizeof(dp));
         f(i,,n-)
             f(j,,n-)
             {
                 scan(Map[i][j]);
             }
         dp[][]=dfs(,);
         pf("%d\n",dp[][]);
     }
  }