BZOJ 1606: [Usaco2008 Dec]Hay For Sale 购买干草( dp )

--------------------------------------------------------------------

#include<cstdio>#include<algorithm>#include<iostream>#include<cstring> #define rep( i , n ) for( int i = 0 ; i < n ; ++i )#define clr( x , c ) memset( x , c , sizeof( x ) ) using namespace std; const int maxn = 50000 + 5; bool dp[ maxn ]; int main() { freopen( "test.in" , "r" , stdin ); clr( dp , 0 ); int n , V; cin >> V >> n; while( n-- ) { int t; scanf( "%d" , &t ); for( int i = 0 ; i + t <= V ; i++ ) if( dp[ i ] ) dp[ i + t ] = true; dp[ t ] = true; } for( int i = V ; i >= 0 ; i-- ) if( dp[ i ] ) { cout << i << "\n"; break; } return 0;}

--------------------------------------------------------------------

1606: [Usaco2008 Dec]Hay For Sale 购买干草

Time Limit: 5 Sec Memory Limit: 64 MB
Submit: 743 Solved: 560
[Submit][Status][Discuss]

Description

约翰遭受了重大的损失：蟑螂吃掉了他所有的干草，留下一群饥饿的牛．他乘着容量为C(1≤C≤50000)个单位的马车，去顿因家买一些干草． 顿因有H(1≤H≤5000)包干草，每一包都有它的体积Vi(l≤Vi≤C).约翰只能整包购买，他最多可以运回多少体积的干草呢？

Input

第1行输入C和H，之后H行一行输入一个Vi．

Output

最多的可买干草体积．

Sample Input

7 3 //总体积为7,用3个物品来背包
2
6
5

The wagon holds 7 volumetric units; three bales are offered for sale with
volumes of 2, 6, and 5 units, respectively.

Sample Output

7 //最大可以背出来的体积

HINT

Buying the two smaller bales fills the wagon.

Source

Silver