zoj 1366 Cash Machine

背包问题，二进制分割

#include <bits/stdc++.h>
using namespace std;

int main()
{
	int crase,nn;
	while(~scanf("%d%d",&crase,&nn)){
		
	int dd[10005];
	int num=0;
	for (int i=0;i<nn;i++){
		int n,d;
		scanf("%d%d",&n,&d);
		int s=1;
		while(n){
			if (n<=s){
				dd[num++]=n*d;
				break;
			}
			dd[num++]=s*d;
			n-=s;
			s=s*2;
		}
	}
	
	
	int ans[100005];
	memset(ans,0,sizeof(ans));
	ans[0]=1;
	
	for (int s=0;s<num;s++){
		for (int i=crase;i>=dd[s];i--){
			ans[i]=ans[i-dd[s]]|ans[i];
		}
	}
	
	
	for (int i=crase;i>=0;i--){
		if (ans[i]){
			printf("%d\n",i);
			break;
		}
	}
	}
	return 0;
}