为什么全都紫了？

#include<bits/stdc++.h>
using namespace std;
int main(){
	int n,k,a = 0,b = 0,za = 0,zb = 0;
	double ansa = za/a,ansb = zb/b;
	cin>>n>>k;
	for (int i = 1;i<=n;i++){
		if (i%k == 0){
			a++;
			za += i;
		}
		else{
			b++;
			zb += i;
		}
	}
	printf("%.1lf %.1lf\n",ansa,ansb);
	return 0;
}