NYOJ106背包问题

 
#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<iostream>
#include <algorithm>
using namespace std;
typedef struct Node
{
	int v;
	int w;
}bag;
bag b[50];
int total = 0;
void greedySelect(bag b[], int s, int m);
int m = 0;
bool cmp(bag a, bag b)//降序;
{
	return a.v > b.v;
}
int main(void)
{
	int n;
	int s;
	scanf("%d", &n);
	while(n--)
	{
		scanf("%d%d", &s, &m);
		memset(b, 0, 50 * sizeof(b[0]));
		for(int i = 0; i < s; i++)
		{
			scanf("%d%d", &b[i].v, &b[i].w);
		}	
		sort(b, b + s, cmp);
		total = 0;
		greedySelect(b, s, m);
		printf("%d\n", total);
	}
	return 0;
}
void greedySelect(bag b[], int s, int m)
{
	int c = m;
	int i;
	for(i = 0; i < s && b[i].w <= c; i++)
	{
		total += b[i].w * b[i].v;
		c -= b[i].w;
	}
	if(i < s)//将第i个物品的一部分装入包中;
	{
		total += c * b[i].v;
	}
}