Plotze - Selection Sort

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <conio.h>
#define MAX 50

int i, j, a[MAX];
char b;

void createArray(int *a) {
    srand(time(NULL));
    for (i = 0; i < MAX; i++)
        a[i] = rand() % 100;
}

void printArray(int a[]) {
    for (i = 0; i < MAX; i++)
        printf("%i ", a[i]);
    printf("\n");
}

void selection_sort(int *a) {
    for (i = 0; i < MAX; i++) {
        int lower_index = i;
        int lower_number = a[i];

        for (j = i + 1; j < MAX; j++) {
            if (a[j] < lower_number) {
                lower_index = j;
                lower_number = a[j];
            }
        }

        int x = a[i];
        a[i] = a[lower_index];
        a[lower_index] = x;
    }
}

int main()
{
    do {
        createArray(a);
        printf("Random array: ");
        printArray(a);

        selection_sort(a);
        printf("Sorted array: ");
        printArray(a);

        b = getch();
        printf("\n");
    } while (b != 27);

    return 0;
}