C Exercises: Insertion sort algorithm

C Programming Searching and Sorting Algorithm: Exercise-3 with Solution

Write a C program to sort a list of elements using the insertion sort algorithm.

Note:
Insertion sort is a simple sorting algorithm that builds the final sorted array (or list) one item at a time. It is much less efficient on large lists than other algorithms such as quicksort, heapsort, or merge sort.

Visual presentation - Insertion search algorithm:

Sample Solution:

Sample C Code:

#include<stdio.h>

int main() {
    int arra[10], i, j, n, array_key;

    // Input the number of values in the array
    printf("Input no. of values in the array: \n");
    scanf("%d", &n);

    // Input array values
    printf("Input %d array value(s): \n", n);
    for (i = 0; i < n; i++)
        scanf("%d", &arra[i]);

    /* Insertion Sort */
    for (i = 1; i < n; i++) {
        array_key = arra[i];
        j = i - 1;

        // Move elements greater than array_key to one position ahead of their current position
        while (j >= 0 && arra[j] > array_key) {
            arra[j + 1] = arra[j];
            j = j - 1;
        }

        // Insert array_key at its correct position
        arra[j + 1] = array_key;
    }

    // Print the sorted array
    printf("Sorted Array: \n");
    for (i = 0; i < n; i++)
        printf("%d  \n", arra[i]);

    return 0;
}

Sample Input:

3
12
15
56

Sample Output:

Input  no. of values in the array: 
Input  3 array value(s): 
Sorted  Array: 
12  
15  
56  

Flowchart:

C Programming Code Editor:

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