题解 | 最简真分数

#include<stdio.h>

int gcd(int a,int b){
	while(a%b !=0){
		int temp = b;
		b = a%b;
		a = temp;
	}
	return b;
}
int main(){
	int n;
	while(scanf("%d",&n) != EOF){
		if(n == 0){
			break;
		}
		int a[n];
		for(int i = 0;i<n;i++){
			scanf("%d",&a[i]);
		}
		int count = 0;
		for(int i = 0;i<n-1;i++){
			for(int j = i+1;j<n;j++){
				if(gcd(a[i],a[j]) == 1){
					count++;
				}
			}
		}
		printf("%d\n",count);
	}
	return 0;
}