c++ code for insertion sort

Certainly! Here's a C++ code example for insertion sort, along with explanations for each step:

#include <iostream>
using namespace std;

void insertionSort(int arr[], int n) {
    int i, key, j;
    for (i = 1; i < n; i++) {
        key = arr[i];
        j = i - 1;

        // Move elements of arr[0..i-1], that are greater than key, to one position ahead of their current position
        while (j >= 0 && arr[j] > key) {
            arr[j + 1] = arr[j];
            j = j - 1;
        }
        arr[j + 1] = key;
    }
}

int main() {
    int arr[] = { 64, 34, 25, 12, 22, 11, 90 };
    int n = sizeof(arr) / sizeof(arr[0]);

    insertionSort(arr, n);

    cout << "Sorted array: \n";
    for (int i = 0; i < n; i++)
        cout << arr[i] << " ";
    cout << endl;

    return 0;
}

Explanation for each step:

  1. The insertionSort function takes an array arr and its size n as parameters.
  2. Inside the function, we declare variables i, key, and j. i is used as a loop counter, key is used to store the current element being sorted, and j is used to compare and shift elements.
  3. The outer for loop starts from the second element (i = 1) and iterates up to the last element (i < n).
  4. Inside the loop, we assign arr[i] to key and i - 1 to j.
  5. The inner while loop checks if j is greater than or equal to 0 and if the element at arr[j] is greater than key.
  6. If the condition is true, we shift the element at arr[j] one position ahead (arr[j + 1] = arr[j]) and decrement j.
  7. We repeat the while loop until j becomes less than 0 or the element at arr[j] is not greater than key.
  8. Finally, we assign key to arr[j + 1] to place the key element in its correct sorted position.
  9. The main function initializes an array arr with values and calculates the size n of the array.
  10. It calls the insertionSort function passing the array and its size.
  11. After sorting, it prints the sorted array using a for loop.
  12. The program then ends by returning 0.

I hope this code example and explanation are helpful! Let me know if you need further assistance.