Question

Create a CodeBlocks project "HW 9"

Write the code to ask the user to enter the size of an array. Then create an integer array of that exact size.

Ask the user to enter a maximum value and then write a loop to fill the array with random numbers with value in the range of 1 to the maximum value. For example, if the maximum value is 100, random numbers must have value 1 to 100 inclusive.

Input size of the array must be greater than 1. Display error if this is not true and exit the program.

Input maximum value of random numbers must be greater than 9. Display error if this is not true and exit the program.

The program should find the smallest, the largest, and median value of the array. To find these values, the array must be sorted in ascending order (low value to high value)

Requirement:

Write a function that calculates median value using this EXACT prototype:

double median(int sortedNumbers[ ], int size)

Parameters:

    sortedNumbers: array that is already sorted before the function is called

    size: this is the input array size

Return: median value

main() function sorts the numbers then passes the array to the median function.

Feel free to define other functions as you want, but make sure you have function prototypes.

How to sort array

For example,

Array

  3 1 4 10 9 7

Sorted Array

  1 3 4 7 9 10

Use the sort() function in the C++ algorithm #include header to sort the array.

1/1 sort() Example using arrays. 2 // By Zereo 04/22/13 3 #include <iostream> 4 #include <algorithm> 6 using namespace std; e const int SIZE = 7; 10 int main() int intArray[SIZE] = {5, 3, 32, -1, 1, 104, 53}; 13 / /Now we call the sort function sort(intArray, intArray + SIZE); cout << "Sorted Array looks like this." << endl; for (size t i = 0; i != SIZE; ++i) cout << intArray[i] < " "; 9 return 0;

Note that our array size is a VARIABLE input by the user, not a constant as seen in the example.

After sorting the array, write the code to find the smallest, largest and call median() function using the sorted array.

The Median is the "middle" number of a sorted array.

How to get median

For example

For Array with odd size 5:

1 3 7 9 9

                      ^

                       | median

The median is 7 (subscript 2). Note that array size is 5 and note that 2 = 5/2 (integer divide)

There are 2 numbers below and 2 numbers above the median 7

For Array with even size 6:

1 3 4 7 9 12

                              ^

                               | median

                           

The median is the average of the two middle numbers, (4 + 7) / 2 = 5.5

Note that subscript of number 4 is 2 (= 6 / 2 - 1) and subscript of number 7 is 3 (= 6 / 2)

There are 3 numbers below the median and 3 numbers above the median.

Notice that the median can have a decimal fraction even when the numbers are all integers, and that the median value may not be in the array.

You can use this code to test your median function with simple sorted arrays:

int size1 = 5;

int sortedArr[ size1 ] = { 1, 3, 7, 9, 9 };

double med = median(sortedArr , size1);

cout << med; // Should get result 7

int size2 = 6;

int sortedArr2[ size2 ] = { 1,3,4,7,9,12};

double med2 = median(sortedArr2 , size2);

cout << med2; // Should get result 5.5

Sample execution

Second run of program:

$DCK9t_3FJkXIeXLOm2g6aJQ6iKBMQfMpF2rApZb8$

Third run of program:

Fourth run of program:

THERE IS NO NEED TO USE ANY LOOP EXCEPT FOR A LOOP THAT FILLS ARRAY WITH RANDOM NUMBERS.

Remember to use srand() to seed the random generator once.

Answer 1

Here's the .cpp code for finding median value as mentioned in question!

#include<iostream>
#include<algorithm>
#include<stdlib.h>
#include<time.h>
using namespace std;
double median(int sortedArray[],int size) {
if(size%2 == 0) { // for even size
return (sortedArray[size/2] + sortedArray[size/2-1]) / 2.0;
}
else { // for odd size
return (double)sortedArray[size/2];
}
}
int main() {
cout<<"This program generates random numbers and finds the median value.";
cout<<"\nEnter the count of random numbers: ";
int size;
cin>>size;
if(size <= 1) {
cout<<"Count must be greater than 1";
exit(0);
}
int intArray[size];
cout<<"\nEnter the maximum value of random numbers: ";
int max_value;
cin>>max_value;

if(max_value <= 9) {
cout<<"\nMaximum value must be greater than 9";
exit(0);
}

int greatestElement = 0; //initializing with minimum value which is zero
int smallestElement = INT_MAX; //initializing with maximum value an integer can hold

//filling array with random values.
srand(time(0)); //seeding random generator
for(int i=0;i<size;i++) {
intArray[i] = rand() % max_value + 1;
smallestElement = min(smallestElement,intArray[i]);
greatestElement = max(greatestElement,intArray[i]);
}
cout<<"\nThe smallest number is "<<smallestElement;
cout<<"\nThe largest number is "<<greatestElement;

//sorting array
sort(intArray, intArray+size);

//call to function median with sorted array and size of array
double myMedian = median(intArray,size);
cout<<"\nThe median number is "<<myMedian;
}