背包问题

将背包装满，要求时间复杂度最小 给定参数，背包容量S=100，N个物品，重量分别为1,55,2,44,3,5,3,56,7,3,5...

<pre name="code" class="cpp">class Test
{
public:	
	//将背包装满，要求时间复杂度最小 给定参数，背包容量S=100，N个物品，重量分别为1,55,2,44,3,5,3,56,7,3,5...
	vector<int> ve;
	void fill_bag(int S, int object_weight[], int len)
	{		
		//一参是数组，二参数组元素数量，三参每个元素的字节数，四参数是函数
		qsort(object_weight,len,sizeof(int),compare);		
		for(int i=len-1; i>=0; i--)
		{
			int c = S;
			int j = i;
			while(j>=0 && c>0)
			{
				j = bi_search(object_weight, j, c);
				if(j==-1)
					break;
				ve.push_back(object_weight[j]);
				if(object_weight[j]==c)
				{
					//ve.push_back(object_weight[j]);
					for(int k=0; k<ve.size(); k++)
						cout<<ve[k]<<" ";
					return;
				}				
				c = c-object_weight[j];
			}
			ve.clear();
		}
		
	}
	
};

int compare(const void *a,const void *b)
{
	return *(int *)a-*(int *)b;
}
//二分查找离元素（可以等于）
int bi_search(int num[10], int len, int target)
{
	int begin = 0;
	int end = len-1;	
	while(begin<end)
	{
		int mid = (begin+end)/2;		
		//最近的一个
		if(num[mid]==target)
			return mid;
		else if(num[mid]>target)
			end = mid-1;
		else
			begin = mid+1;
	}
	cout<<"begin:"<<begin<<"end:"<<end<<endl;
	if(begin==end && begin==0)
		return -1;
	return end;
}
void main1()
{
	int num[10]={11,35,65,25,79,54,34,66,92,30};
	qsort(num,10,sizeof(int),compare);
	for(int i=0;i<10;i++)
		cout<<num[i]<<" ";
	cout<<endl;
	int index = bi_search(num, 10, 36);
	cout<<index<<endl;
}

int main()
{
	//int num[10]={11,35,65,25,79,54,34,66,92,30};
	int num[10]={11,25,30,34,35,54,65,66,79,92};
	Test t;
	t.fill_bag(100, num, 10);
	return 0;
}