Find nth Ugly number.

//https://leetcode.com/problems/ugly-number-ii/


class Solution {
public:
    int nthUglyNumber(int n) {
        
        
                int dp [ n ] ; 
                dp [ 0 ] = 1 ; 
                int n2 , n3 , n5 ; 
                n2 = n3 = n5 = 0 ; 
                for ( int i = 1 ; i < n ; i ++ )
                {
                    int mini = min ( dp [ n2 ] * 2 , min ( dp [ n3 ] * 3 , dp [ n5 ] * 5 ) ) ; 
                    dp [ i ] = mini ; 
                    if ( mini == dp [ n2 ] * 2 )
                        n2 ++ ; 

                    if ( mini == dp [ n3 ] * 3 )
                        n3 ++ ; 

                    if ( mini == dp [ n5 ] * 5 )
                        n5 ++ ;

                }

                return dp [ n - 1 ] ; 

    }
};