in;10000 19;out:5006.5,5000.2而我out:5006.5,5000.0
#include <stdio.h>
int main()
{
int n,k, a = 0, b = 0; float sum1 = 0; float sum2 = 0;
scanf("%d %d", &n,&k);
for(int i = 1; i <= n; i++)
{
if (i %k== 0)
{
sum1 += i;
a++;
}
else
{
sum2 += i;
b++;
}
}
printf("%.1f %.1f", sum1 / a, sum2 / b);
return 0;
}