1012 数字分类，C

不清楚1分的错误点在哪

#include <stdio.h>
int main()
{
	int q[1000] = {0};
    int n,i,a1=0,a2=0,a3=0,aa4=0,a5=0,m=0;
	int a22 = 1;
    float a4 = 0;
    scanf("%d",&n);
    for(i=0; i<n; i++)
        scanf("%d",&q[i]);

    i = 0;
    while(q[i])
    {
        if(q[i]%2==0 && q[i]%5==0)
            a1 += q[i];
        else if(q[i]%5==1)
        {
            if(a22 % 2 == 1)	a2 = a2 + q[i];
			else a2 = a2 - q[i];
			a22++;
        }
        else if(q[i]%5==2)
            a3++;
        else if(q[i]%5==3)
            {a4+= q[i];     aa4++;}
        else if(q[i]%5==4)
        {
            if(q[i] > a5)    a5 = q[i];
        }
        i++;
    }    

    if(a1)      printf("%d ",a1);    else    printf("N ");
    if(a2)      printf("%d ",a2);    else    printf("N ");
    if(a3)      printf("%d ",a3);    else    printf("N ");
    if(a4)      printf("%.1f ",a4/aa4);    else    printf("N ");
    if(a5)      printf("%d",a5);    else    printf("N");

	
    return 0;
}