POJ3624:Charm Bracelet[01背包]

2014-11-24 02:59:08 · 作者: · 浏览: 1

Description

Bessie has gone to the mall's jewelry store and spies a charm bracelet. Of course, she'd like to fill it with the best charms possible from the N (1 ≤ N ≤ 3,402) available charms. Each charm i in the supplied list has a weight Wi (1 ≤ Wi ≤ 400), a 'desirability' factor Di (1 ≤ Di ≤ 100), and can be used at most once. Bessie can only support a charm bracelet whose weight is no more than M (1 ≤ M ≤ 12,880).

Given that weight limit as a constraint and a list of the charms with their weights and desirability rating, deduce the maximum possible sum of ratings.

Input

* Line 1: Two space-separated integers: N and M
* Lines 2..N+1: Line i+1 describes charm i with two space-separated integers: Wi and Di

Output

* Line 1: A single integer that is the greatest sum of charm desirabilities that can be achieved given the weight constraints

Sample Input

4 6
1 4
2 6
3 12
2 7Sample Output

23 题意:经典0—1背包问题,有n个物品,编号为i的物品的重量为w[i],价值为v[i],现在要从这些物品中选一些物品装到一个容量为m的背包中,使得背包内物体在总重量不超过m的前提下价值尽量大. #include
#include int max(int a ,int b)
{
return a>b a:b;
}int main()
{
int n,m,w[40000],d[40000],i,j;
int dp[40000];
while(~scanf("%d%d",&n,&m))
{
memset(dp,0,sizeof(dp));
for(i = 0;i for(i = 0;i {
for(j = m;j>=w[i];j--)
{
dp[j] = max(dp[j],dp[j-w[i]]+d[i]);
}
}
printf("%d\n",dp[m]);
} return 0;
}