#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <pthread.h>

#define MATRIX_SIZE 4  // Size of the matrix (example 4x4)
#define NUM_THREADS (MATRIX_SIZE * 2)  // Number of threads for matrix's rows and columns

int matrix[MATRIX_SIZE][MATRIX_SIZE];
pthread_barrier_t barrier;

// Function to swap two elements
void swap(int *a, int *b) {
    int temp = *a;
    *a = *b;
    *b = temp;
}

// Function executed by each thread to sort a row or column
void *sort_row_or_column(void *arg) {
    int index = *(int*)arg;
    for (int phase = 0; phase < MATRIX_SIZE; phase++) {
        for (int i = 0; i < MATRIX_SIZE - 1; i++) {
            if (index < MATRIX_SIZE) {
                // Sort a row
                if ((phase % 2 == 0 && matrix[index][i] > matrix[index][i + 1]) || 
                    (phase % 2 != 0 && matrix[index][i] < matrix[index][i + 1])) {
                    swap(&matrix[index][i], &matrix[index][i + 1]);
                }
            } else {
                // Sort a column
                int col = index - MATRIX_SIZE;
                if (matrix[i][col] > matrix[i + 1][col]) {
                    swap(&matrix[i][col], &matrix[i + 1][col]);
                }
            }
        }
        // Synchronize all threads at the barrier
        pthread_barrier_wait(&barrier);
    }

    pthread_exit(NULL);
}

int main() {
    pthread_t threads[NUM_THREADS];
    int thread_args[NUM_THREADS];
    int status;

    // Initialize the matrix and barrier
    srand(time(NULL));  // Seed for random numbers
    for (int i = 0; i < MATRIX_SIZE; i++) {
        for (int j = 0; j < MATRIX_SIZE; j++) {
            matrix[i][j] = rand() % 100;  // Random numbers between 0 and 99
        }
    }
    pthread_barrier_init(&barrier, NULL, NUM_THREADS);

    // Create threads for sorting
    for (int i = 0; i < NUM_THREADS; i++) {
        thread_args[i] = i;
        status = pthread_create(&threads[i], NULL, sort_row_or_column, (void *)&thread_args[i]);

        if (status != 0) {
            printf("ERROR; return code from pthread_create() is %d\n", status);
            exit(-1);
        }
    }

    // Wait for all threads to complete
    for (int i = 0; i < NUM_THREADS; i++) {
        pthread_join(threads[i], NULL);
    }

    // Print the sorted matrix
    printf("Sorted Matrix:\n");
    for (int i = 0; i < MATRIX_SIZE; i++) {
        for (int j = 0; j < MATRIX_SIZE; j++) {
            printf("%d ", matrix[i][j]);
        }
        printf("\n");
    }

    // Clean up and exit
    pthread_barrier_destroy(&barrier);

    return 0;
}