题解 | #数位五五#

int main()
{
    int a,b;
    scanf("%d %d",&a,&b);
    int i = 0;
    int count = 0;
    for(i=a;i<=b;i++)
    {
        int k = i;
        int sum = 0;
        
        while(k)
        {
            int n = k%10;
            sum+=n;
            k/=10;
        }
        if(sum%5==0)
        {
            count++;
        }
    }
    printf("%d\n",count);
    return 0;
}