[BZOJ1606][Usaco2008 Dec]Hay For Sale 购买干草

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

Time Limit: 5 Sec  Memory Limit: 64 MB Submit: 1349  Solved: 999 [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.

 

裸的背包

#include <cstdio>
int C, H, v;
bool dp[50000 + 10] = {false};
int main(){
    scanf("%d %d", &C, &H);
    dp[0] = true;
    for(int i = 1; i <= H; i++){
        scanf("%d", &v);
        for(int j = C; j >= v; j--)
            dp[j] |= dp[j - v];
    }
    int ans;
    for(int i = C; ~i; i--)
        if(dp[i]){
            ans = i;
            break;
        }
    printf("%d\n", ans);
    return 0;
}