insertion_sort.c

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

void print_array(int *array, int array_size);

int main(int argc, char **argv) {
  int *array;
  int array_size;
  int i = 0;
  int left = 0;
  int tmp;
  
  if (argc < 2) {
    printf("Usage: %s [size of list]\n", argv[0]);
    return 1;
  }

  srand(time(NULL));
  array_size = atoi(argv[1]);
  array = calloc(array_size, sizeof(int));

  for (int k = 0; k < array_size; k++)
    array[k] = rand() % 100;

  print_array(array, array_size);
  printf("\n");

  while (++i < array_size) {
    if (array[i] > array[i - 1])
      continue;

    left = i;
    tmp = array[i];

    while (tmp < array[--left]) {
      array[left + 1] = array[left];
      array[left] = tmp;
    }
  }

  print_array(array, array_size);
  return 0;
}

void print_array(int *array, int array_size) {
  for (int i = 0; i < array_size; i++) {
    printf(" %d ", array[i]);
  }
  printf("\n");
}