sem4-problem3-mergesort

#include <stdio.h>
#include <string.h>
#define MAX_ARR_SIZE 3000
#define MAX_STR_LEN 100

char a[MAX_ARR_SIZE][MAX_STR_LEN],
        b[MAX_ARR_SIZE][MAX_STR_LEN];

void mergeSort(int l, int r)
{
    if (l == r)
        return;

    int m = (l + r) / 2;
    mergeSort(l, m);
    mergeSort(m + 1, r);

    int i = l, j = m + 1, k = l;
    while (i <= m || j <= r)
        if (i > m || (j <= r && strcmp(a[i], a[j]) > 0))
            strcpy(b[k++], a[j++]);
        else
            strcpy(b[k++], a[i++]);
    for (i = l; i <= r; i++)
        strcpy(a[i], b[i]);
}

int main(int argc, char const *argv[])
{
    int i, n;
    printf("Number of lines to sort: ");
    scanf("%d", &n);
    for (i = 0; i < n; i++)
        scanf("%s", a[i]);

    mergeSort(0, n - 1);

    printf("\n");
    for (i = 0; i < n; i++)
        printf("%s\n", a[i]);

    return 0;
}