Skip to content
Related Articles

Related Articles

Improve Article
Count of sub-strings of length n possible from the given string
  • Last Updated : 07 May, 2021

Given a string str and an integer N, the task is to find the number of possible sub-strings of length N.
Examples: 
 

Input: str = “geeksforgeeks”, n = 5 
Output:
All possible sub-strings of length 5 are “geeks”, “eeksf”, “eksfo”, 
“ksfor”, “sforg”, “forge”, “orgee”, “rgeek” and “geeks”.
Input: str = “jgec”, N = 2 
Output:
 

 

Approach: The count of sub-strings of length n will always be len – n + 1 where len is the length of the given string. For example, if str = “geeksforgeeks” and n = 5 then the count of sub-strings having length 5 will be “geeks”, “eeksf”, “eksfo”, “ksfor”, “sforg”, “forge”, “orgee”, “rgeek” and “geeks” which is len – n + 1 = 13 – 5 + 1 = 9.
Below is the implementation of the above approach: 
 

C++




// C++ implementation of the approach
#include <bits/stdc++.h>
using namespace std;
 
// Function to return the count of
// possible sub-strings of length n
int countSubStr(string str, int n)
{
    int len = str.length();
    return (len - n + 1);
}
 
// Driver code
int main()
{
    string str = "geeksforgeeks";
    int n = 5;
 
    cout << countSubStr(str, n);
 
    return 0;
}

Java




// Java implementation of the approach
import java.util.*;
 
class GFG
{
 
// Function to return the count of
// possible sub-strings of length n
static int countSubStr(String str, int n)
{
    int len = str.length();
    return (len - n + 1);
}
 
// Driver code
public static void main(String args[])
{
    String str = "geeksforgeeks";
    int n = 5;
 
    System.out.print(countSubStr(str, n));
}
}
 
// This code is contributed by mohit kumar 29

Python3




# Python3 implementation of the approach
 
# Function to return the count of
# possible sub-strings of length n
def countSubStr(string, n) :
 
    length = len(string);
    return (length - n + 1);
 
# Driver code
if __name__ == "__main__" :
 
    string = "geeksforgeeks";
    n = 5;
 
    print(countSubStr(string, n));
     
# This code is contributed by Ryuga

C#




// C# implementation of the approach
using System;
 
class GFG
{
 
// Function to return the count of
// possible sub-strings of length n
static int countSubStr(string str, int n)
{
    int len = str.Length;
    return (len - n + 1);
}
 
// Driver code
public static void Main()
{
    string str = "geeksforgeeks";
    int n = 5;
 
    Console.WriteLine(countSubStr(str, n));
}
}
 
// This code is contributed by Code_Mech.

PHP




<?php
// PHP implementation of the approach
 
// Function to return the count of
// possible sub-strings of length n
function countSubStr($str, $n)
{
    $len = strlen($str);
    return ($len - $n + 1);
}
 
// Driver code
$str = "geeksforgeeks";
$n = 5;
 
echo(countSubStr($str, $n));
 
// This code is contributed by Code_Mech.
?>

Javascript




<script>
  // JavaScript implementation of the approach
  // Function to return the count of
  // possible sub-strings of length n
  function countSubStr(str, n) {
    var len = str.length;
    return len - n + 1;
  }
 
  // Driver code
  var str = "geeksforgeeks";
  var n = 5;
 
  document.write(countSubStr(str, n));
</script>
Output: 
9

 

Attention reader! Don’t stop learning now. Get hold of all the important DSA concepts with the DSA Self Paced Course at a student-friendly price and become industry ready.  To complete your preparation from learning a language to DS Algo and many more,  please refer Complete Interview Preparation Course.

In case you wish to attend live classes with industry experts, please refer DSA Live Classes 




My Personal Notes arrow_drop_up
Recommended Articles
Page :