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 = “w3wiki” 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++
#include <bits/stdc++.h>
using namespace std;
int countSubStr(string str, int n)
{
int len = str.length();
return (len - n + 1);
}
int main()
{
string str = "w3wiki" ;
int n = 5;
cout << countSubStr(str, n);
return 0;
}
|
Java
import java.util.*;
class GFG
{
static int countSubStr(String str, int n)
{
int len = str.length();
return (len - n + 1 );
}
public static void main(String args[])
{
String str = "w3wiki" ;
int n = 5 ;
System.out.print(countSubStr(str, n));
}
}
|
Python3
def countSubStr(string, n) :
length = len (string);
return (length - n + 1 );
if __name__ = = "__main__" :
string = "w3wiki" ;
n = 5 ;
print (countSubStr(string, n));
|
C#
using System;
class GFG
{
static int countSubStr( string str, int n)
{
int len = str.Length;
return (len - n + 1);
}
public static void Main()
{
string str = "w3wiki" ;
int n = 5;
Console.WriteLine(countSubStr(str, n));
}
}
|
Javascript
<script>
function countSubStr(str, n) {
var len = str.length;
return len - n + 1;
}
var str = "w3wiki" ;
var n = 5;
document.write(countSubStr(str, n));
</script>
|
PHP
<?php
function countSubStr( $str , $n )
{
$len = strlen ( $str );
return ( $len - $n + 1);
}
$str = "w3wiki" ;
$n = 5;
echo (countSubStr( $str , $n ));
?>
|
Time Complexity: O(1), it is a constant.
Auxiliary Space: O(1), no extra space is required.
Count of sub-strings of length n possible from the given string
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 = “w3wiki”, n = 5
Output: 9
All possible sub-strings of length 5 are “geeks”, “eeksf”, “eksfo”,
“ksfor”, “sforg”, “forge”, “orgee”, “rgeek” and “geeks”.
Input: str = “jgec”, N = 2
Output: 3
Recommended: Please try your approach on {IDE} first, before moving on to the solution.