sort_matrix_extract_unique_elements.c

/*

    sort_matrix_extract_unique_elements.c

    Sort the matrix and extract the unique elements.

https://www.faceprep.in/c/program-to-remove-duplicate-elements-in-an-array/


    You can find all my C programs at Dragan Milicev's pastebin:

    https://pastebin.com/u/dmilicev

*/

#include <stdio.h>

#define MAX_SIZE 10
//#define ROWS 10
//#define COLUMNS 10

// Displays array arr[] that has n elements
// text[] describes the shown array arr[]
void display_array(char text[],int arr[],int n)
{
    int i;

    printf("%s",text);
    for(i=0;i<n;i++)
        printf("%4d", arr[i]);

    printf("\n");
}

// Displays a matrix M [] [] that has r rows and c columns
void display_matrix( char *text, int M[][MAX_SIZE], int r, int c )
{
    int i, j;

    printf("\n%s\n\n",text);

    for(i=0;i<r;i++) {                  // print matrix M[][]
        for(j=0;j<c;j++)
            printf(" %4d", M[i][j]);

        printf("\n\n");                 // new row of matrix
    }
}

// function bubbleSort to sort the array arr[] of n elements in descending order
void bubbleSort(int arr[], int n)
{
    int i, j, temp;

    for (i = 0; i < n-1; i++)
        for (j = 0; j < n-i-1; j++)     // Last i elements are already in place
            if (arr[j] < arr[j+1])      // arr[j] > arr[j+1] for ascending order
            {
                temp = arr[j];
                arr[j] = arr[j+1];
                arr[j+1] = temp;
            }
}

// remove duplicate elements in an sorted array
int remove_duplicate_elements(int arr[], int n)
{
    if (n==0 || n==1)
        return n;

    int temp[n];
    int j = 0;
    int i;

    for (i=0; i<n-1; i++)
        if (arr[i] != arr[i+1])
            temp[j++] = arr[i];

    temp[j++] = arr[n-1];

    for (i=0; i<j; i++)
        arr[i] = temp[i];

    return j;
}


int main(void)
{
    int i, j, k=0, r=3, c=3, n=r*c;
    // r is the number of rows and c is the number of columns of the matrix M[][]

    int M[MAX_SIZE][MAX_SIZE] = { { 5, 4, 5 },
                                  { 2, 0, 4 },
                                  { 1, 5, 2 }  };   // matrix
    int arr[n];     // array

    // collecting matrix elements in an array
    for(i=0; i<r; i++)
        for(j=0; j<c; j++)
            arr[k++] = M[i][j];

    display_matrix(" \n MATRIX = \n", M, r, c);

    display_array("\n\tARRAY = ", arr, n);

    bubbleSort(arr,r*c);

    display_array("\n SORTED ARRAY = ", arr, n);

    n = remove_duplicate_elements(arr,n);

    display_array("\n UNIQUE ARRAY = ", arr, n);


    return 0;

} // main()