HNU2[I题]Omar Loves Candies 贪心

 1 // File Name: I.cpp
 2 // Author: darkdream
 3 // Created Time: 2014年07月20日 星期日 13时07分24秒
 4 
 5 #include<vector>
 6 #include<list>
 7 #include<map>
 8 #include<set>
 9 #include<deque>
10 #include<stack>
11 #include<bitset>
12 #include<algorithm>
13 #include<functional>
14 #include<numeric>
15 #include<utility>
16 #include<sstream>
17 #include<iostream>
18 #include<iomanip>
19 #include<cstdio>
20 #include<cmath>
21 #include<cstdlib>
22 #include<cstring>
23 #include<ctime>
24 #define LL long long
25 
26 using namespace std;
27 LL dp[1004][1004];
28 int p[1005];
29   int n , m ; 
30 LL ans(int i , int j)
31 {
32     if(j > m )
33       return -2LL*1e9;
34     return dp[n][m] - dp[i-1][m] - dp[n][j-1] + dp[i-1][j-1]; 
35 }
36 int main(){
37   int t; 
38   scanf("%d",&t);
39   while(t--)
40   {
41     scanf("%d %d",&n,&m);
42     memset(dp,0,sizeof(dp));
43     memset(p,0,sizeof(p));
44     int temp ;
45     for(int  i =1;i <= n;i ++)
46     {
47       int sum = 0 ; 
48       for(int j =1;j <= m;j ++)
49       {
50          scanf("%d",&temp);
51          sum += temp;
52          dp[i][j] = dp[i-1][j] + sum;
53          if(temp < 0)
54              p[i]++;
55       }
56     }
57     LL a = max(ans(n,p[n]+1),1LL*temp);
58     temp = p[n]+1;
59     for(int i = n-1;i >= 1;i --)
60     {
61        for(int j = temp;j <= p[i]+1;j ++)
62        {
63           if(ans(i,j) >= a)
64           {
65              a = ans(i,j);
66              temp = j; 
67           }
68        }
69     }
70     printf("%lld\n",a);
71   }
72   
73 return 0;
74 }