Q4) A class named findmin has been designed to find the minimum element in an
array.
Class name findmin
Data member
int a[] // integer array of size 5
Member Functions
void enterdata() // to store 5 integer elements in the array
void findmin() // to find the minimum element in the array and display
Answers
Explanation:
Write a C function to return minimum and maximum in an array. Your program should make the minimum number of comparisons.
Recommended: Please solve it on “PRACTICE ” first, before moving on to the solution.
First of all, how do we return multiple values from a C function? We can do it either using structures or pointers.
We have created a structure named pair (which contains min and max) to return multiple values.
struct pair
{
int min;
int max;
};
And the function declaration becomes: struct pair getMinMax(int arr[], int n) where arr[] is the array of size n whose minimum and maximum are needed.
METHOD 1 (Simple Linear Search)
Initialize values of min and max as minimum and maximum of the first two elements respectively. Starting from 3rd, compare each element with max and min, and change max and min accordingly (i.e., if the element is smaller than min then change min, else if the element is greater than max then change max, else ignore the element)
// C++ program of above implementation
#include<iostream>
using namespace std;
// Pair struct is used to return
// two values from getMinMax()
struct Pair
{
int min;
int max;
};
struct Pair getMinMax(int arr[], int n)
{
struct Pair minmax;
int i;
// If there is only one element
// then return it as min and max both
if (n == 1)
{
minmax.max = arr[0];
minmax.min = arr[0];
return minmax;
}
// If there are more than one elements,
// then initialize min and max
if (arr[0] > arr[1])
{
minmax.max = arr[0];
minmax.min = arr[1];
}
else
{
minmax.max = arr[1];
minmax.min = arr[0];
}
for(i = 2; i < n; i++)
{
if (arr[i] > minmax.max)
minmax.max = arr[i];
else if (arr[i] < minmax.min)
minmax.min = arr[i];
}
return minmax;
}
// Driver code
int main()
{
int arr[] = { 1000, 11, 445,
1, 330, 3000 };
int arr_size = 6;
struct Pair minmax = getMinMax(arr, arr_size);
cout << "Minimum element is "
<< minmax.min << endl;
cout << "Maximum element is "
<< minmax.max;
return 0;
}
// This code is contributed by nik_3112
Output:
Minimum element is 1
Maximum element is 3000
Time Complexity: O(n)
In this method, the total number of comparisons is 1 + 2(n-2) in the worst case and 1 + n – 2 in the best case.
In the above implementation, the worst case occurs when elements are sorted in descending order and the best case occurs when elements are sorted in ascending order.
METHOD 2 (Tournament Method)
Divide the array into two parts and compare the maximums and minimums of the two parts to get the maximum and the minimum of the whole array.