Print All Substrings of a String

“Print all substrings of a String” is a popular technical interview problem asked in many interviews. Here, we are given a string of length ‘n’ and our task is write a program to count and print all substrings of a string. 

Example:

INPUT:
ABCD
OUTPUT:
No of substring: 10
Substrings: A, B, C, D, AB, BC, CD, ABC, BCD, ABCD

The steps required to count and print all substrings of a string are as follows:

1. Set count = 0.
2. Three nested loops will be taken.
3. The outer loop will be used to take the starting character of the substring.
4. The middle loop will be used to take the last character of the substring.
5. The inner loop will be used to print the substring from starting character (from outer loop) to ending character (from middle loop). Increment count by 1.

C++ Program to count and print all substrings of a string are as follows:

/* C++ Program to count and print all substrings of a string */
#include<bits/stdc++.h>  
using namespace std;  
int main()  
{  
    string str;  
    cout<<"Enter a string:\n";  
    cin>>str;  
    int count = 0;  
    cout<<"The substring are:\n";  
    int size = str.length();  
    /* Outer loop for starting character of substring */  
    for(int i = 0; i < size; i++)  
    {  
        /* Middle loop for ending character of substring */  
        for(int j = i; j < size; j++)  
        {  
            string substring = "";  
            /* Inner loop for creating substring */  
            for(int k = i; k <= j; k++)  
            {  
                substring = substring + str[k];  
            }  
            count++;  
            cout<<substring<<"\n";  
        }  
    }  
    cout<<"The number of substrings are "<<count;  
}  

OUTPUT:
Enter a string: ABCD
The substring are:
A
AB
ABC
ABCD
B
BC
BCD
C
CD
D
The number of substrings are 10
Time Complexity:
O(n^3), where n is the length of the string

Related Posts:

1. Program to find longest palindromic Substring.
2. Program to check Anagram Strings.
3. Program to check whether two Strings are Rotation of each other or not.
4. Program to check Palindromic Anagram.
5. Program to print all the Palindromic Substring of the String.
6. Program to check Panagram String.
7. Program to find first non-repeating character of the String.
8. Program to print all possible subarrays of the given array.
9. Program to print kth smallest and kth largest element of an Array.
10. Program to find equilibrium index of an Array.
11. Program to find majority element of an Array.
12. Program to find mean of the Array.
13. Program to sort an Array of 0s and 1s.
14. Program to find first repeating element of an array.
15. Program to merge two sorted arrays.
16. Program to find missing number in an array.
17. Program to sort if array is sorted.
18. Program to print Alternate Elements of an Array.
19. Program to swap kth element from beginning to kth element from end in an Array.
20. Program to print all possible subarrays of the given array.