How to Sort a String in CPP: Efficient Algorithms Explained

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Rearranging an array’s elements logically is known as sorting in C++. You can order the highest to lowest or lowest to highest here. For example, the most minor or maximum element is one of many issues that can be resolved by sorting an unsorted array. 

You can sort a string in C++ using four methods. They are Bubble Sort, Selection Sort, Insertion Sort, and Quick Sort. Bubble sort is claimed to be the best method of all. It compares the first two numbers and swaps them if the first one is greater than the other. The most effective and quick way is the Quick Sort. It divides the array into subarrays and sorts them individually.

Sort String in C++

This article will look into sorting algorithms to sort a string in C++.

How To Sort A String In C++ | 4 Ways

Given below are some of the ways to sort a string in C++.

By Bubble Sort 

In terms of sorting algorithms, bubble sorting is one of the best. In this sorting method, you can start by comparing the array’s first two elements to see if the first is greater than the second one. If it is, swap the two and then move on to the next element. Up until the array’s finding, this operation will keep repeating.

Bubble Sorting

These examples include 12, 3, 1, 5, 18, 10, 7, and 35. To sort this array, you have to use two loops, the first from 0 to 8 and the second repeating from i+1 to 8. ‘j’ will be at index 1, when ‘i’ is at index 0, and ‘j’ will be at index 0+1. As a result, there will be a comparison between ‘element 0’ and ‘element 1’.

The switching will happen if the element at index 1 is smaller than at index 0. Likewise, each element will have a comparison with the subsequent element individually, and so on, until the final element.

Final Output 

Bubble Sorting Output

By Selection Sorting

Using the selection sorting technique, you can locate the minor element by comparing it to the other elements. It is then sorted at the top of the array. The array is split in half, with the sorted subarray on the left and the unsorted subarray on the right.

Selection Sorting

Selection Sorting

From 0 to num-1, the first for loop will repeat. The first element is set to the minor variables inside the for loop block, and the element’s index is assigned to the P variable.

The loop contains an if statement that instructs you to assign the element to the minor variables if arr[j] is less than the minimum element and to assign the index of that element to P if it is less than the minimum element.

We will replace arr[i] with arr[P] because P allocates the index. We will print the sorted array once the swapping is complete.

Final Output 

Selection Sorting Output

By Insertion Sort

This sorting method compares items to their prototypes to determine their order. The comparison of the second and first elements serves as the starting point. In this case, you will switch the elements if the second element is smaller than the first.

Insertion Sorting

In this example, Following input, you use a for loop, repeating from 1 to num-1; the loop begins at 1 because the comparison will start at index 1.

The while loop contains the condition if the temp is less than arr[j], which means that if temp, which is storing the index 1 element, is less than arr[j], which is the index 0 elements, you will move arr[j] to its proper location, i.e., arr[j+1].

Final Output

Insertion Sorting Output

By Quick Sort

The most popular sorting algorithm and most effective sorting algorithm are quicksorts. It utilizes the divide and sorting strategy, dividing the array into smaller subarrays. When these smaller subarrays have been sorted, they are combined to create a more extensive sorted array.

Quick Sort

In this example, you give the array to the Quick function along with its starting index of 0 and its last index of num-1 after receiving the array as input from the user.

A conditional statement inside the Quick function specifies that only the if block will run if the array has more than one element and the start index is less than the end index. The pivot element is given the final element inside this division function.

Final Output

Quick Sort Output

By using all these methods, you can sort a string in C++.


How does C++'s sorting of strings work?

To sort strings in C++, use the std::sort function from the C++ Standard Library. The sorting algorithm known as ‘introsort,’ which is a hybrid sorting algorithm combining three different algorithms. These are quicksort, heapsort, and insertion sort, is implemented by the std::sort function. Std::sort uses lexicographic (dictionary) order to sort strings by operating on their characters.

How long does it take to sort a string in C++?

When using the std::sort function from the C++ Standard Library to sort a string, the time complexity is O(N log N). Here N is the length of the string. The introsort algorithm, a hybrid sorting algorithm that combines quicksort, heapsort, and insertion sort. The std::sort function typically uses it. Moreover, when the recursion depth reaches a certain point, the algorithm switches from quicksort to heapsort.

Can C++ sort a string of numbers?

Yes, C++ can sort a string of numbers. Since a string in C++ is simply an array of characters, you can sort the characters in the string in lexicographic (dictionary) order. Using the std::sort function from the C++ Standard Library will also sort the string of numbers.

How does sorting by strings operate?

String sorting, also called lexicographic sorting, compares characters in a string and arranges them alphabetically or in dictionary order. During sorting, C++ compares characters one by one at the beginning of the string until it discovers a difference or the string ends.

Which string sorting algorithm is the best?

The ideal string sorting algorithm will vary depending on your specific needs and the properties of the data you're sorting. Additionally, the performance characteristics of various sorting algorithms vary. In summary, the best option may change depending on the data size, the strings' distribution, and your application's limitations.

What sorting algorithm is the quickest?

The hybrid sorting algorithm known as Introsort (Combining Quicksort, Heapsort, and Insertion Sort) combines quicksort, heapsort, and insertion sort. -Merge Sort: Merge sort is adequate for handling large datasets and has a stable time complexity of O(N log N). -The radix sort can be speedy for sorting strings of similar lengths or fixed-length integers.


After reading this article on sorting in C++, you better understand sorting and how to use sorting methods like bubble, insertion, quick, etc.  You have also gained an understanding of the usefulness of the sorting methods through the use of examples.

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