// There is a problem in this source file related to
// array indices being out of bounds. First, compile
// this file by issuing the following command:
//
// gcc -g -Wall -std=gnu99 -o backtrace backtrace.c
//
// Next, run the program under GDB:
//
// gdb ./backtrace
//
// Set a conditional breakpoint to take a look at the
// status of the variables inside of the Store()
// function when index is greater than 100. As with
// conditional.c, it may be obvious what the problem
// is but it would still be good practice to pretend
// to investigate what is going on with the code.
//
// Some commands you'll want to use:
// "b" to set a breakpoint
// "n" to move to the next statement, skipping over
//     function calls
// "s" to step to the next statement, not skipping
//     over function calls
// "p" to print values
// "bt" to print a backtrace of the call stack for
//     the current state of the program
// "frame" to switch to a different stack frame to
//     look at the variables in it
//
// The section slides have more information, and you
// can also use "help [command]" within GDB to see
// how to use them.

#include <stdio.h>

static void Store(int* array, int index, int value) {
  array[index] = value;
}

// Append the contents of array a to the end of array
// b. a_len is the number of elements in array a and
// b_len is the number of elements in array b, so at
// the end array b should contain a_len + b_len elements
// in total.
static void Append(int* a, int a_len, int* b, int b_len) {
  for (int i = 0; i < b_len; ++i) {
    Store(b, b_len + i, a[i]);
  }
}

int main(int argc, char* argv[]) {
  // Create an array of size 100 and store 40 values
  // in it.
  int a[100];
  int a_len = 40;
  for (int i = 0; i < a_len; ++i) {
    a[i] = i;
  }

  // Create an array of size 100 and store 60 values
  // int it.
  int b[100];
  int b_len = 60;
  for (int i = 0; i < b_len; ++i) {
    b[i] = i;
  }

  // Append the contents of array a to the end of array
  // b and then print the combination of the two.
  Append(a, a_len, b, b_len);
  for (int i = 0; i < a_len + b_len; ++i) {
    printf("%d\n", b[i]);
  }

  return 0;
}