UVA 443 SOLUTION

#include<cstdio>
#include<set>
#include<vector>
#include<algorithm>
#include<stdlib.h>
#include<cstring>
#include<string>
using namespace std;
typedef long long int lld;

int main()
{
    int a[4]={2,3,5,7};
    set<lld> s;
    set <lld> :: iterator it;
    s.insert(1);
    it=s.begin();
    while (s.size()<5842)
    {
        for (int i=0;i<4;i++)
        {
            lld b=*it*a[i];
            if (b<2000000001) s.insert(b);
        }
        it++;
    }
    vector<lld> humble(s.begin(),s.end());
   
    int n;
    while (scanf("%d",&n)==1)
    {
        if (n==0) return 0;
        string c;
        if (n%10==1 && (n%100)/10!=1) c="st";
        else if (n%10==2 && (n%100)/10!=1) c="nd";
        else if (n%10==3 && (n%100)/10!=1) c="rd";
        else c="th";
        printf("The %d%s humble number is %lld.\n",n,c.c_str(),humble[n-1]);
    }
    return 0;
}