HDU 1171 背包问题

Big Event in HDU

Time Limit: 10000/5000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)
Total Submission(s): 14529    Accepted Submission(s): 5111

Problem Description

Nowadays, we all know that Computer College is the biggest department in HDU. But, maybe you don't know that Computer College had ever been split into Computer College and Software College in 2002.
The splitting is absolutely a big event in HDU! At the same time, it is a trouble thing too. All facilities must go halves. First, all facilities are assessed, and two facilities are thought to be same if they have the same value. It is assumed that there is N (0

 

Input

Input contains multiple test cases. Each test case starts with a number N (0 < N <= 50 -- the total number of different facilities). The next N lines contain an integer V (0 A test case starting with a negative integer terminates input and this test case is not to be processed.

 

Output

For each case, print one line containing two integers A and B which denote the value of Computer College and Software College will get respectively. A and B should be as equal as possible. At the same time, you should guarantee that A is not less than B.

 

Sample Input

2 10 1 20 1 3 10 1 20 2 30 1 -1

 

Sample Output

20 10 40 40

 

Author

lcy

此题可转换为01背包问题。

#include 
#include 
#include 
using namespace std;
int  F[250002];
int main()
{
	int N,V[51],M[51],i,j;  //N为物品种类数，V[]为价值，M[]为数目 
	while(cin>>N) 
	{
		if(N < 0)break;
	 	int	sum = 0;
		for(i = 0; i < N; i++)
		{
			cin>>V[i]>>M[i];
			sum += V[i]*M[i];
		}
		
		int sum1 = sum / 2;
		memset(F,0,sizeof(F));   //置0 
		for(i = 0; i < N; i++)   //01背包问题 
		{
			for(j = 0; j < M[i]; j++)     //限定数目 
				for(int k = sum1; k >= V[i]; k--)    
				{
					F[k] = max(F[k], F[k-V[i]]+V[i]);
				}
		}
		
		cout<

代码挺费时的，虽然没有超时，但是比起别人代码来，还是慢了很多的。

哪儿还可以优化下呢？

求指教~~~