TCS Coding Practice Question | LCM of 2 Numbers
Given two numbers, the task is to find the LCM of two numbers using Command Line Arguments. LCM (Least Common Multiple) of two numbers is the smallest number which can be divided by both numbers. For example, LCM of 15 and 20 is 60 and LCM of 5 and 7 is 35. Examples:
Input: n1 = 10, n2 = 15 Output: 30 Input: n1 = 5, n2 = 10 Output: 10
Approach:
- Since the numbers are entered as Command line Arguments, there is no need for a dedicated input line
- Extract the input numbers from the command line argument
- This extracted numbers will be in string type.
- Convert these numbers into integer type and store it in variables, say num1 and num2
- Find the LCM of the numbers. An efficient solution is based on the below formula for LCM of two numbers ‘a’ and ‘b’.
a x b = LCM(a, b) * GCD (a, b) LCM(a, b) = (a x b) / GCD(a, b)
- To find the GCD or HCF, an efficient solution is to use Euclidean algorithm, which is the main algorithm used for this purpose. The idea is, GCD of two numbers doesn’t change if a smaller number is subtracted from a bigger number.
- Print or return the LCM
Program:
C
// C program to compute the LCM of two numbers // using command line arguments #include <stdio.h> #include <stdlib.h> /* atoi */ // Function to compute the GCD of two numbers int GCD( int a, int b) { if (b == 0) return a; return GCD(b, a % b); } // Function to find the LCM int LCM( int a, int b) { return (a * b) / GCD(a, b); } // Driver code int main( int argc, char * argv[]) { int num1, num2; // Check if the length of args array is 1 if (argc == 1) printf ( "No command line arguments found.\n" ); else { // Get the command line argument and // Convert it from string type to integer type // using function "atoi( argument)" num1 = atoi (argv[1]); num2 = atoi (argv[2]); // Find the LCM and print it printf ( "%d\n" , LCM(num1, num2)); } return 0; } |
Java
// Java program to compute the LCM of two numbers // using command line arguments class GFG { // Function to compute the GCD of two numbers static int GCD( int a, int b) { if (b == 0 ) return a; return GCD(b, a % b); } // Function to find the LCM static int LCM( int a, int b) { return (a * b) / GCD(a, b); } // Driver code public static void main(String[] args) { // Check if length of args array is // greater than 0 if (args.length > 0 ) { // Get the command line argument and // Convert it from string type to integer type int num1 = Integer.parseInt(args[ 0 ]); int num2 = Integer.parseInt(args[ 1 ]); // Find the LCM int res = LCM(num1, num2); // Print the LCM System.out.println(res); } else System.out.println( "No command line " + "arguments found." ); } } |
Output:
- In C:
- In Java:
Time Complexity : O(logN)
Auxiliary Space: O(logN)