Codevs 1014(装箱问题)

#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <algorithm>
#include <cstring>
#include <stack>
#include <cctype>
#include <queue>
#include <string>
#include <vector>
#include <set>
#include <map>
#include <climits>
#define lson root<<1,l,mid
#define rson root<<1|1,mid+1,r
#define fi first
#define se second
#define ping(x,y) ((x-y)*(x-y))
#define mst(x,y) memset(x,y,sizeof(x))
#define mcp(x,y) memcpy(x,y,sizeof(y))
using namespace std;
#define gamma 0.5772156649015328606065120
#define MOD 1000000007
#define inf 0x3f3f3f3f
#define N 1000005
#define maxn 100005
typedef pair<int,int> PII;
typedef long long LL;

int n,m,ans;
int a[50];
int dp[20005];

int main(){
int i,j;
scanf("%d%d",&n,&m);
for(i=1;i<=m;++i)scanf("%d",&a[i]);
for(i=1;i<=m;++i){
for(j=n;j>=a[i];--j)
dp[j]=max(dp[j],dp[j-a[i]]+a[i]);
}
printf("%d\n",n-dp
);
return 0;
}