The ugly Numbers of Geeks face examination questions

Ugly Numbers

Ugly numbers are numbers whose only prime factors 2, 3 or 5. The sequence

1, 2, 3, 4, 5, 6, 8, 9, 10, 12, 15, ...

Shows the ugly numbers. By convention, 1 is included.

Write a program to find and print the 150′th ugly number.

Method 1 (Simple)

Nedylko Draganov for suggesting this solution.

Algorithm:

loop for all positive integers until ugly # count is smaller than n, if a integer is ugly than increment ugly Count.

To check if a are ugly, divide the number by greatest divisible powers of 2, 3 and 5, if the number becomes 1 then I T is a ugly number otherwise not.

For example, let us??? Check for/is ugly or not. Greatest divisible power of 2 are 4 after dividing to 4 we get 75. Greatest divisible power of 3 are 3 after dividing to 3 we get 25. Greatest divisible power of 5 was, after dividing and we get 1. Since we get 1 Finally, the ugly is number.

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Here's a simple method with a program that can print all ugly number less than N:

int maxdivide (int num, int div)  
{while  
    (num% div = = 0)  
    {  
        num/= div;  
    }  
    return num;  
}  
     
BOOL isugly (int num)  
{  
    num = maxdivide (num, 2);  
    num = Maxdivide (num, 3);  
    num = maxdivide (num, 5);  
    return num = 1? True:false;  
}  
     
int Getnthuglyno (int n)  
{  
    int c = 0;  
    int i = 0;  
    while (c < n)  
    {  
        if (isugly (++i)) C + +;  
    }  
    return i;  
}  
#include <vector>  
using Std::vector;  
vector<int> Getalluglyno (int n)  
{  
    vector<int> rs;  
    for (int i = 1; I <= n; i++)  
    {  
        if (isugly (i)) rs.push_back (i);  
    }  
    return RS;  
}