Space Elevator

U - Space Elevator

Time Limit:1000MS     Memory Limit:65536KB     64bit IO Format:%I64d & %I64u

Submit  Status

Description

The cows are going to space! They plan to achieve orbit by building a sort of space elevator: a giant tower of blocks. They have K (1 <= K <= 400) different types of blocks with which to build the tower. Each block of type i has height h_i (1 <= h_i <= 100) and is available in quantity c_i (1 <= c_i <= 10). Due to possible damage caused by cosmic rays, no part of a block of type i can exceed a maximum altitude a_i (1 <= a_i <= 40000). 

Help the cows build the tallest space elevator possible by stacking blocks on top of each other according to the rules.

Input

* Line 1: A single integer, K 

* Lines 2..K+1: Each line contains three space-separated integers: h_i, a_i, and c_i. Line i+1 describes block type i.

Output

* Line 1: A single integer H, the maximum height of a tower that can be built

Sample Input

3
7 40 3
5 23 8
2 52 6

Sample Output

48

Hint

OUTPUT DETAILS: 

From the bottom: 3 blocks of type 2, below 3 of type 1, below 6 of type 3. Stacking 4 blocks of type 2 and 3 of type 1 is not legal, since the top of the last type 1 block would exceed height 40.

      这题的数据挺坑的，网上说什么要考虑输出0的情况，但我的wa代码已过了我自己想的一些情况，就是一直wa。最后就直接用个变量算了。终于AC了。我个人比较推荐用变量存储的方法，因为这样比较鲁棒.(ps:这题想了有一天了，结果发现要排序，先考虑小的)

AC代码：

#include<iostream>
#include<algorithm>
#include<cstring>
#include<string>
#include<cstdio>
using namespace std;
struct S
{
	int h,m,c;
	friend bool operator<(const S& a,const S& b)
	{
		return a.m<b.m; 
	}
}a[500];
int dp[40500];
int main()
{
	/*freopen("input.txt","r",stdin);*/
	int n,i,j,k,ma;
	while(~scanf("%d",&n))
	{
		ma = 0;
		memset(dp,0,sizeof(dp));
		for(i=0;i<n;++i)
		{
			scanf("%d%d%d",&a[i].h,&a[i].m,&a[i].c);
		}
		sort(a,a+n);
		for(i=0;i<n;++i)
		{
			for(j=a[i].m;j>=a[i].h;--j)
			{
				for(k=1;k<=a[i].c&&j>=k*a[i].h;++k)
				{
				  dp[j]=max(dp[j],dp[j-k*a[i].h]+k*a[i].h);
				  if(ma<dp[j])ma = dp[j];
				}                                                                                                                                                                                                                                                                                                            
			}
		}
		printf("%d\n",ma);
	}
	return 0;
}

WA代码：

#include<iostream>
#include<algorithm>
#include<cstring>
#include<string>
#include<cstdio>
#include<queue>
using namespace std;
struct S
{
	int h,m,c;
	friend bool operator<(const S& a,const S& b)
	{
		return a.m<b.m; 
	}
}a[500];
int dp[40500];
int main()
{
	/*freopen("input.txt","r",stdin);*/
	int n,i,j,k,ma=0;
	scanf("%d",&n);
	memset(dp,0,sizeof(dp));
	for(i=0;i<n;++i)
	{
		scanf("%d%d%d",&a[i].h,&a[i].m,&a[i].c);
		if(ma<a[i].m)ma=a[i].m;
	}
	sort(a,a+n);
	int tmp;
	for(i=0;i<n;++i)
	{
		for(j=a[i].m;j>=a[i].h;--j)
		{
			for(k=1;k<=a[i].c&&j>=k*a[i].h;++k)
			{
				tmp = dp[j-k*a[i].h]+k*a[i].h;
				dp[j]=max(dp[j],tmp);
			}                                                                                                                                                                                                                                                                                                            
		}
	}
	printf("%d\n",dp[ma]);
	return 0;
}