hrbust 1241 Blocks【暴力枚举+简单优化】

BlocksTime Limit: 1000 MSMemory Limit: 65536 KTotal Submit: 77(30 users)Total Accepted: 47(28 users)Rating: Special Judge: NoDescriptionDonald wishes to send a gift to his new nephew, Fooey. Donald is a bit of a traditionalist, so he has chosen to send a set of N classic baby blocks. Each block is a cube, 1 inch by 1 inch by 1 inch. Donald wants to stack the blocks together into a rectangular solid and wrap them all up in brown paper for shipping. How much brown paper does Donald need?InputThe first line of input contains C, the number of test cases. For each case there is an additional line containing N, the number of blocks to be shipped. N does not exceed 1000.Output

Your program should produce one line of output per case, giving the minimal area of paper (in square inches) needed to wrap the blocks when they are stacked together.

Sample Input

59102627100

Sample Output

30348254130

SourceWaterloo local 2002.09.21Recommend程宪庆

题目大意：

给你n个1*1*1大小的立方体，让你将其包装起来，而且要求包装起来的形状必须是正方体/长方体，问最少包装纸花费。

思路：

1、首先我们知道，一个长方体/正方体最重要的三个元素就是：长、宽、高。那么我们想办法找出来长宽高abc使得其外表面积最小即可。

2、找了半天规律，最后入手点发现应该在n<=1000上边。因为n并不大，我们可以通过枚举a，b然后用n/a*b得到c，如果此时a、b、c的方案是一种可行方案，那么a*b*2+b*c*2+a*c*2就是一种可行方案解，然后我们一直枚举下去，维护最小方案值即可。

3、简单优化：如果a*b>n跳出即可。

Ac代码：

#include<stdio.h>#include<iostream>#include<string.h>using namespace std;int main(){    int t;    scanf("%d",&t);    while(t--)    {        int n;        int output=0x3f3f3f3f;        scanf("%d",&n);        for(int i=1;i<=n;i++)        {            for(int j=1;j<=n;j++)            {                if(i*j>n)break;                int a=i,b=j;                int c=n/(a*b);                if(a*b*c==n)                {                    output=min(output,a*b*2+b*c*2+a*c*2);                }            }        }        printf("%d\n",output);    }}