Minimum number of operations required to delete all elements of the array using C++.

Problem statement

Given an integer array arr, the task is to print the minimum number of operations required to delete all elements of the array. While deleting element following restriction is imposed −

• Any element from the array can be chosen at random and every element divisible by it can be removed from the array

If arr[] = {2, 4, 15, 10, 8, 5, 3} then 3 operation are required to delete all elements −

• If we choose 2 then it will delete {2, 4, 10, 8}
• If we choose 5 then it will remove {5, 15}
• If we choose 3 then it will remove {3}

Algorithm

1. Sort the array in ascending order and count number occurrence of each element
2. For each unmarked element starting from beginning mark all elements which are divisible by choose element, and increase the result counter

Example

#include <iostream>
#include <algorithm>
#define SIZE(arr) (sizeof(arr) / sizeof(arr[0]))
#define MAX 100
using namespace std;
int getMinOperations(int *arr, int n){
   int map[MAX] = {0};
   sort(arr, arr + n);
   for (int i = 0; i < n; ++i) {
      map[arr[i]]++;
   }
   int cnt = 0;
   for (int i = 0; i < n; ++i) {
      if (map[arr[i]]) {
         for (int j = i; j < n; ++j) {
            if (arr[j] % arr[i] == 0) {
               map[arr[j]] = 0;
            }
         }
         ++cnt;
      }
   }
   return cnt;
}
int main(){
   int arr[] = {2, 4, 15, 10, 8, 5, 3};
   cout << "Minimum required operations = " << getMinOperations(arr, SIZE(arr)) << endl;
   return 0;
}

Output

When you compile and execute the above program. It generates the following output −

Minimum required operations = 3

Narendra Kumar

Published on 31-Oct-2019 07:21:16

• Related Questions & Answers
• Minimum delete operations to make all elements of array same in C++.
• Minimum operations required to make all the array elements equal in C++
• Minimum operations required to set all elements of binary matrix in C++
• Minimum number of operations on an array to make all elements 0 using C++.
• Number of operations required to make all array elements Equal in Python
• Minimum number of operations required to sum to binary string S using C++.
• Minimum number of mails required to distribute all the questions using C++.
• Minimum number of given operations required to make two strings equal using C++.
• Minimum operations required to remove an array in C++
• Minimum number of moves to make all elements equal using C++.
• How to find the minimum number of jumps required to reach the end of the array using C#?
• Minimum number of swaps required to sort an array in C++
• Count the number of operations required to reduce the given number in C++
• Finding minimum number of required operations to reach n from m in JavaScript
• Minimum operations of given type to make all elements of a matrix equal in C++