hdu 1058 humble numbers

#include<iostream>
#include<cstring>
#include<algorithm>
#include<cstdio>
#include<vector>
#include<string>
#include<cmath>
#include<deque>
#include<map>
#include<queue>
#define iinf 0x7f7f7f7f
#define linf 1000000000000000000LL
#define dinf 1e200
#define eps 1e-11
#define lng long long
#define sqr(a) ((a)*(a))
#define pii pair<int,int>
#define X first
#define Y second
#define pi 3.14159265359
#define cc(i,j) memset(i,j,sizeof(i))
#define two(x)          ((lng)1<<(x))
#define mod  9901
#define pmod(x,y) (x%y+y)%y
#include<set>
using namespace std;
typedef vector<int>  vi;
typedef vector<string>  vs;
template<class T> inline void checkmax(T &x,T y){if(x<y) x=y;}
template<class T> inline void checkmin(T &x,T y){if(x>y) x=y;}
template<class T> inline T Min(T x,T y){return (x>y?y:x);}
template<class T> inline T Max(T x,T y){return (x<y?y:x);}
template<class T> T Abs(T a){return a>0?a:(-a);}
int a[5843];
int main()
{
a[1]=1;
for(int ii=2,i=1,j=1,k=1,z=1;ii<=5842;++ii)
{
int ans=Min(Min(a[i]*2,a[j]*3),Min(a[k]*5,a[z]*7));
if(ans==a[i]*2) ++i;
if(ans==a[j]*3) ++j;
if(ans==a[k]*5) ++k;
if(ans==a[z]*7) ++z;
a[ii]=ans;
}
int n;
char b[3];
b[3]='\0';
while(scanf("%d",&n)==1&&n)
{
int k=n%100,f=n%10;
strcpy(b,"th");
if(k!=11&&f==1) strcpy(b,"st");
if(k!=12&&f==2) strcpy(b,"nd");
if(k!=13&&f==3) strcpy(b,"rd");
printf("The %d%s humble number is %d.\n",n,b,a
);
}
return 0;
}