HDU 1058 Humble Numbers

#include <iostream>
#include <cstring>
#include <cstdio>
#include <algorithm>
using namespace std;
int a[5850]= {0,1};
int main()
{
    int k=1,n;
    int b2,b3,b5,b7;
    b2=b3=b5=b7=1;
    while(k<=5842)
    {
        a[++k]=min(2*a[b2],min(3*a[b3],min(5*a[b5],7*a[b7])));
        if(a[k]==2*a[b2])
            b2++;
        if(a[k]==3*a[b3])
            b3++;
        if(a[k]==5*a[b5])
            b5++;
        if(a[k]==7*a[b7])
            b7++;
    }
    while(~scanf("%d",&n),n)
    {
        if(n%10==1&&n%100!=11)
            printf("The %dst humble number is %d.\n",n,a[n]);
        else if(n%10==2&&n%100!=12)
            printf("The %dnd humble number is %d.\n",n,a[n]);
        else if(n%10==3&&n%100!=13)
            printf("The %drd humble number is %d.\n",n,a[n]);
        else
            printf("The %dth humble number is %d.\n",n,a[n]);
    }
    return 0;
}