UglyNumbers.java

// Java program to find nth ugly number 
class GFG { 
	
	/*This function divides a by greatest 
	divisible power of b*/
	static int maxDivide(int a, int b) 
	{ 
		while(a % b == 0) 
			a = a/b; 
		return a; 
	} 
	
	/* Function to check if a number 
	is ugly or not */
	static int isUgly(int no) 
	{ 
		no = maxDivide(no, 2); 
		no = maxDivide(no, 3); 
		no = maxDivide(no, 5); 
		
		return (no == 1)? 1 : 0; 
	} 
	
	/* Function to get the nth ugly 
	number*/
	static int getNthUglyNo(int n) 
	{ 
		int i = 1; 
		
		// ugly number count 
		int count = 1; 
		
		// check for all integers 
		// until count becomes n 
		while(n > count) 
		{ 
			i++; 
			if(isUgly(i) == 1) 
				count++; 
		} 
		return i; 
	} 
	
	/* Driver program to test above 
	functions */
	public static void main(String args[]) 
	{ 
		int no = getNthUglyNo(150); 
		System.out.println("150th ugly "
					+ "no. is "+ no); 
	} 
}