原题链接:https://vjudge.net/contest/331993#problem/I
Vladik and Chloe decided to determine who of them is better at math. Vladik claimed that for any positive integer n he can represent fraction as a sum of three distinct positive fractions in form
.
Help Vladik with that, i.e for a given n find three distinct positive integers x, y and z such that . Because Chloe can't check Vladik's answer if the numbers are large, he asks you to print numbers not exceeding 109.
If there is no such answer, print -1.
Input
The single line contains single integer n (1 ≤ n ≤ 104).
Output
If the answer exists, print 3 distinct numbers x, y and z (1 ≤ x, y, z ≤ 109, x ≠ y, x ≠ z, y ≠ z). Otherwise print -1.
If there are multiple answers, print any of them.
Examples
3
2 7 42
7
7 8 56
简单来说,就是对于给定的n,构建一组x,y,z,使得1/x + 1/y +1/z =2/ n 然后 当n=1的时候 输出-1
#include<bits/stdc++.h> using namespace std; int main() { int n; cin>>n; if(n==1) cout<<"-1"<<endl; else cout<<n<<endl<<n+1<<endl<<n*(n+1); return 0; }
其实, 可以看作,