POJ 1338 Ugly Numbers 寻找丑数

/*Ugly Numbers
Time Limit: 1000MS  Memory Limit: 10000K
Total Submissions: 13272  Accepted: 5856

Description

Ugly numbers are numbers whose only prime factors are 2, 3 or 5. The sequence
1, 2, 3, 4, 5, 6, 8, 9, 10, 12, ...
shows the first 10 ugly numbers. By convention, 1 is included.
Given the integer n,write a program to find and print the n'th ugly number.

Input

Each line of the input contains a postisive integer n (n <= 1500).Input is terminated by a line with n=0.
Output

For each line, output the n’th ugly number .:Don’t deal with the line with n=0.
Sample Input

1
2
9
0

Sample Output

1
2
10

Source

New Zealand 1990 Division I,UVA 136
*/

#include <stdio.h>

#define  MAX_NUM_OF_UNGLY_NUMBER  1501

int gaiUnglyNum[MAX_NUM_OF_UNGLY_NUMBER];

#define MIN(a,b)  (((a) < (b)) ? (a) : (b))
#define THREE_MIN(a,b,c) MIN(MIN(a,b),c)

int UglyNumbersmain(void)
{
int iLoop;
int iLoop2 = 1;
int iLoop3 = 1;
int iLoop5 = 1;
int iNthUgly;

gaiUnglyNum[1] = 1;

for (iLoop = 2; iLoop < MAX_NUM_OF_UNGLY_NUMBER; iLoop++)
{
while (gaiUnglyNum[iLoop2]*2 <= gaiUnglyNum[iLoop-1])
{
iLoop2++;
}
while (gaiUnglyNum[iLoop3]*3 <= gaiUnglyNum[iLoop-1])
{
iLoop3++;
}
while (gaiUnglyNum[iLoop5]*5 <= gaiUnglyNum[iLoop-1])
{
iLoop5++;
}

gaiUnglyNum[iLoop] = THREE_MIN(gaiUnglyNum[iLoop2]*2,gaiUnglyNum[iLoop3]*3,gaiUnglyNum[iLoop5]*5);
}

while(1)
{
scanf("%d",&iNthUgly);
if (0 == iNthUgly)
{
break;
}

printf("%d/n",gaiUnglyNum[iNthUgly]);
}

return 0;
}