2018 Multi-University Training Contest 1
A - Maximum Multiple
Given an integer nn, Chiaki would like to find three positive integers xx, yy and zzsuch that: n=x+y+z, x∣nx∣n, y∣ny∣n, z∣nz∣n and xyzxyz is maximum.
Input
There are multiple test cases. The first line of input contains an integer TT (1≤T≤1061≤T≤106), indicating the number of test cases. For each test case:
The first line contains an integer nn (1≤n≤1061≤n≤106).
Output
For each test case, output an integer denoting the maximum xyzxyz. If there no such integers, output −1−1 instead.
Sample Input
3 1 2 3
Sample Output
-1 -1 1
x+y+z=n 若(x>=y>=z)
令a=1/x b=1/y c=1/z;
则1<=a<=3
a=1不可能的。
a=2 :b=4 c=4或 b=3 c=6;
a=3 :b=3 c=3;(包含了上面第二种)
所以只有这两种情况成立啦!
其他都是-1……
#include<cstdio>
#include<iostream>
using namespace std;
int main()
{
int T;
cin>>T;
while(T--)
{
int n;
scanf("%d",&n);
if(n%3==0)
{
printf("%I64d\n", 1ll *n*n*n/27);
}
else if(n%4==0)
printf("%I64d\n", 1ll *n*n*n/32);
else
printf("-1\n");
}
return 0;
}