codeforces 294B Shaass and Bookshelf

 1 /************************************************************
 2  * Author : darkdream
 3  * Email : darkdream1994@gmail.com 
 4  * Last modified : 2015-03-09 20:32
 5  * Filename : 294b.cpp
 6  * Description :
 7  * *********************************************************/
 8 // File Name: 294b.cpp
 9 // Author: darkdream
10 // Created Time: 2015年03月09日 星期一 20时04分53秒
11 
12 #include<vector>
13 #include<list>
14 #include<map>
15 #include<set>
16 #include<deque>
17 #include<stack>
18 #include<bitset>
19 #include<algorithm>
20 #include<functional>
21 #include<numeric>
22 #include<utility>
23 #include<sstream>
24 #include<iostream>
25 #include<iomanip>
26 #include<cstdio>
27 #include<cmath>
28 #include<cstdlib>
29 #include<cstring>
30 #include<ctime>
31 #define LL long long
32 
33 using namespace std;
34 struct node{
35   int t , w; 
36 }a[200];
37 int dp[200][300];
38 int main(){
39     int n; 
40     scanf("%d",&n);
41     memset(dp,-1,sizeof(dp));
42     int total = 0 ; 
43     for(int i = 1;i <= n;i ++)
44     {
45       scanf("%d %d",&a[i].t,&a[i].w);
46       total += a[i].t ;
47     }
48     dp[0][0] = 0 ;
49     int mi = 1e9 ; 
50     for(int i = 1;i <= n;i ++)
51     {
52         for(int j = 0 ;j <= total;j ++)
53         {
54            dp[i][j]  = dp[i-1][j];
55         }
56         for(int j = 0 ;j <= total;j ++)
57         {
58            if(dp[i-1][j] != -1)
59            {
60               if(dp[i-1][j+a[i].t] == -1)
61                   dp[i][j+a[i].t] = dp[i-1][j] + a[i].w; 
62               else dp[i][j+a[i].t] =  min(dp[i][j+a[i].t],dp[i-1][j] + a[i].w);
63            }
64         }
65     }
66     for(int i = 1;i <= n;i ++)
67     {
68         for(int j= 0 ;j <= total ;j ++)
69         {
70          // printf("%d ",dp[i][j]);
71           if(dp[i][j] <= total -j && dp[i][j] != -1)
72               mi = min(mi,total - j );
73         }
74         //printf("\n");
75 
76     }
77     printf("%d\n",mi);
78 return 0;
79 }