codeforces-743C-math

题目大意：给定n，求满足2/n=1/x+1/y+1/z的x,y,z的值

题目解析：想到1/a+1/(a+1)+1/(a*a+a)=2/a，所以我们只要令x=a，y=a+1，z=a*a+a即可，注意n=1的时候y=z不可以；

AC代码：

#include<iostream>#include<cstdio>#include<algorithm>#include<cstring>#include<string>using namespace std;typedef long long ll;const int inf=0x3fffffff;int main(){int n;while(scanf("%d",&n)!=EOF){if(n==1){printf("-1\n");continue;}int a,b,c;a=n;b=n+1;c=n*(n+1);printf("%d %d %d\n",a,b,c);}return 0;}