Question

Write a C++ program to find least common multiple (LCM) of two, three and four integer values. The integer values are entered from the keyboard and the outputs are printed to the console. The LCM of two, three and four integer values are computed using Prime factorization method.

You have to use arrays to hold input values and use functions/methods to get data from the keyboard, display output to the console, calculate LCM using Prime factorization method. Your program should tell to the user that how many values they need to enter (more than 1 and less than 5) and they need to enter input values from 2 to 100. If 2 values (v1,v2) are entered by the user, then the program should compute the LCM of both values. For example, if 3 values (v1, v2, v3) are entered, then the program should be computed and displayed the following:

• LCM(v1,v2)
• LCM(v1,v3)
• LCM(v2,v3)
• LCM(v1,v2,v3)

If 4 values (v1, v2, v3, v4) are entered, then the program should be computed and displayed the following:

• LCM(v1,v2)
• LCM(v1,v3)
• LCM(v1,v4)
• LCM(v2,v3)
• LCM(v2,v4)
• LCM(v3,v4)
• LCM(v1,v2,v3)
• LCM(v1,v2,v4)
• LCM(v1,v3,v4)
• LCM(v2,v3,v4)
• LCM(v1,v2,v3,v4)

Answer 1

Code:

#include <bits/stdc++.h>

using namespace std;

typedef long long int ll;

// Utility function to find

// GCD of 'a' and 'b'

int gcd(int a, int b)

{

if (b == 0)

return a;

return gcd(b, a % b);

}

// Returns LCM of array elements

ll findlcm(int arr[], int n)

{

// Initialize result

ll ans = arr[0];

// ans contains LCM of arr[0], ..arr[i]

// after i'th iteration,

for (int i = 1; i < n; i++)

ans = (((arr[i] * ans)) /

(gcd(arr[i], ans)));

return ans;

}

// Driver Code

int main()

{

int arr[] = { 2, 7, 3, 9, 4 };

int n = sizeof(arr) / sizeof(arr[0]);

printf("%lld", findlcm(arr, n));

return 0;

}

the above-mentioned code is for lcm of an array.

this can be willingly modified by defining the length of array.

that is setting the value of n.

if n = 2 it will take only 2 elements in the array and find lcm if n = 3 then 3 elements and so on.