C Exercises: Return only the unique rows from a given binary matrix

C Array: Exercise-72 with Solution

Write a program in C to return only the unique rows from a given binary matrix.

Expected Output:
The given array is :
0 1 0 0 1
1 0 1 1 0
0 1 0 0 1
1 0 1 0 0
The unique rows of the given array are :
0 1 0 0 1
1 0 1 1 0
1 0 1 0 0

The task is to write a C program that identifies and returns only the unique rows from a given binary matrix. The program should iterate through the matrix, compare each row with the others, and extract only those rows that are distinct from all others. The unique rows should then be displayed in the same order they appear in the original matrix.

Sample Solution:

C Code:

#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>

#define R 4 // Number of rows
#define C 5 // Number of columns

// Struct definition for trie node
typedef struct Node {
    bool chkEndOfCol;      // Indicates the end of a row
    struct Node *child[2]; // Child nodes (left and right)
} myNode;

// Function to create a new node for the trie
myNode* newNode() {
    myNode* temp = (myNode *)malloc( sizeof( myNode ) );
    temp->chkEndOfCol = 0;
    temp->child[0] = temp->child[1] = NULL;
    return temp;
}

// Function to insert a row into the trie
bool insert(myNode** root, int (*arr1)[C], int r, int c) {
    // If root is NULL, create a new node
    if (*root == NULL)
        *root = newNode();

    // If within columns, continue inserting
    if (c < C)
        return insert(&((*root)->child[arr1[r][c]]), arr1, r, c+1);
    else {
        // If end of column, mark it in the trie
        if (!((*root)->chkEndOfCol))
            return (*root)->chkEndOfCol = 1;
        return 0;
    }
}

// Function to print a row of the array
void printRow(int (*arr1)[C], int r) {
    int i;
    for (i = 0; i < C; ++i)
        printf("%d ", arr1[r][i]);
    printf("\n");
}

// Function to find and print unique rows of the array
void findUniqueRows(int (*arr1)[C]) {
    myNode* root = NULL;
    int i;
    printf("The unique rows of the given array are :\n");
    for (i = 0; i < R; ++i) {
        // If row is inserted into trie (i.e., not a duplicate), print the row
        if (insert(&root, arr1, i, 0))
            printRow(arr1, i);
    }
}

int main() {
    int arr1[R][C] = {
        {0, 1, 0, 0, 1},
        {1, 0, 1, 1, 0},
        {0, 1, 0, 0, 1},
        {1, 0, 1, 0, 0}
    };
    int i, j;

    // Print the original array
    printf("The given array is :\n");
    for (i = 0; i < R; i++) {
        for (j = 0; j < C; j++) {
            printf("%d  ", arr1[i][j]);
        } 
        printf("\n");
    }

    // Find and print unique rows of the array
    findUniqueRows(arr1);
    return 0;
}

Output:

The given array is :  
0  1  0  0  1  
1  0  1  1  0  
0  1  0  0  1  
1  0  1  0  0  
The unique rows of the given array are :  
0 1 0 0 1 
1 0 1 1 0 
1 0 1 0 0

Flowchart:

C Programming Code Editor:

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