How to Sort a 2D Array by Column Values in C ?

Sorting a 2D Array by Column Values Using Built-in Functions or Custom Methods in C

In C , unlike Java, there is no direct built-in function that can sort a 2D array by specific column values. However, various approaches can be employed to achieve this desired sorting behavior.

Using C Standard Library Functions

One method involves utilizing the std::qsort function, which is a generic sorting algorithm. By defining a custom comparator function, you can control the sorting logic based on the column values. Here's an example implementation:

<code class="cpp">#include <iostream>
#include <algorithm>

int compareArrayColumns(int **lhs, int **rhs) {
  return (*lhs)[0] <p>In this code, the compareArrayColumns function is used to compare the first column values of each array row. The sorting is performed using the std::qsort function, and the sorted 2D array is printed.</p>
<h3 id="Using-Custom-Methods">Using Custom Methods</h3>
<p>Another approach involves creating custom sorting functions that implement the desired logic. Here's an example implementation using a bubble sort:</p>
<pre class="brush:php;toolbar:false"><code class="cpp">#include <iostream>

void bubbleSortByColumn(int arr[][2], int size) {
  for (int i = 0; i  arr[j + 1][0]) {
        int temp[2];
        temp[0] = arr[j][0];
        temp[1] = arr[j][1];
        arr[j][0] = arr[j + 1][0];
        arr[j][1] = arr[j + 1][1];
        arr[j + 1][0] = temp[0];
        arr[j + 1][1] = temp[1];
      }
    }
  }
}

int main() {
  int arr[][2] = {
    {20, 11},
    {10, 20},
    {39, 14},
    {29, 15},
    {22, 23}
  };

  int size = sizeof(arr) / sizeof(arr[0]);
  bubbleSortByColumn(arr, size);

  for (int i = 0; i <p>In this code, the bubbleSortByColumn function implements a simple bubble sort algorithm that iterates through the array and swaps rows based on the first column values. The sorted 2D array is then printed.</p>
<p>The choice of approach depends on the specific requirements and performance considerations of your application.</p></iostream></code>

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