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# Sub-strings having exactly k characters that have ASCII value greater than p

• Difficulty Level : Easy
• Last Updated : 26 May, 2021

Given a string ‘str’, two integers ‘k’ and ‘p’. The task is to count all the sub-strings of ‘str’ having exactly ‘k’ characters that have ASCII value greater than ‘p’.
Examples:

Input: str = “abcd”, k=2, p=98
Output:
Only the characters ‘c’ and ‘d’ have ASCII values greater than 98,
And, the sub-strings containing them are “abcd”, “bcd” and “cd”.
Input: str = “sabrcd”, k=5, p=80
Output:

Approach: We just need to iterate over all indices and take all possible length sub-strings and then just check whether the sub-string has exactly ‘k’ characters that have ASCII value greater than ‘p’.

Typecasting a character to int will give us it’s ASCII value i.e. int ascii = (int) char.

Below is the implementation of the above approach:

## C++

 `// C++ implementation of the approach``#include ``using` `namespace` `std;` `// Function that checks if``// the string contain exactly``// K characters having ASCII``// value greater than p``bool` `isValidSubString(string r, ``int` `K, ``int` `p)``{``    ``int` `c = 0;` `    ``for` `(``int` `i = 0; i < r.length(); i++) {` `        ``// if ASCII value is``        ``// greater than 'p'``        ``if` `((``int``)r[i] > p)``            ``c++;``    ``}` `    ``// if count of satisfying``    ``// characters is equal to 'K'``    ``// then return true``    ``if` `(c == K)``        ``return` `true``;` `    ``// otherwise return false``    ``else``        ``return` `false``;``}` `// function to count sub-strings``void` `countSubStrings(string s, ``int` `K, ``int` `p)``{``    ``// length of the string``    ``int` `l = s.length();` `    ``// count of sub-strings``    ``int` `count = 0;` `    ``// 'i' is the starting``    ``// index for the sub-string``    ``for` `(``int` `i = 0; i < l; i++) {` `        ``// 'j' is the no. of characters``        ``// to include in the sub-string``        ``for` `(``int` `j = K; (i + j) <= l; j++) {``            ``string r = s.substr(i, j);` `            ``// check if the sub-string``            ``// satisfies the condition``            ``if` `(isValidSubString(r, K, p))``                ``count++;``        ``}``    ``}` `    ``cout << count << ``"\n"``;``}` `// Driver code``int` `main()``{` `    ``string s = ``"abepztydba"``;``    ``int` `K = 4;``    ``int` `p = 110;` `    ``countSubStrings(s, K, p);` `    ``return` `0;``}`

## Java

 `// Java implementation of the approach``class` `GFG {` `    ``// Function that checks if``    ``// the String contain exactly``    ``// K characters having ASCII``    ``// value greater than p``    ``boolean` `isValidSubString(String r, ``int` `K, ``int` `p)``    ``{``        ``int` `c = ``0``;` `        ``for` `(``int` `i = ``0``; i < r.length(); i++) {` `            ``// if ASCII value is``            ``// greater than 'p'``            ``if` `((``int``)r.charAt(i) > p) {``                ``c++;``            ``}``        ``}` `        ``// if count of satisfying``        ``// characters is equal to 'K'``        ``// then return true``        ``if` `(c == K) {``            ``return` `true``;``        ``}` `        ``// otherwise return false``        ``else` `{``            ``return` `false``;``        ``}``    ``}` `    ``// function to count sub-Strings``    ``void` `countSubStrings(String s, ``int` `K, ``int` `p)``    ``{``        ``// length of the String``        ``int` `l = s.length();` `        ``// count of sub-Strings``        ``int` `count = ``0``;` `        ``// 'i' is the starting``        ``// index for the sub-String``        ``for` `(``int` `i = ``0``; i < l; i++) {` `            ``// 'j' is the no. of characters``            ``// to include in the sub-String``            ``for` `(``int` `j = K; (i + j) <= l; j++) {` `                ``String r = s.substring(i, (i + j));` `                ``// check if the sub-String``                ``// satisfies the condition``                ``if` `(isValidSubString(r, K, p)) {``                    ``count++;``                ``}``            ``}``        ``}``        ``System.out.println(count);``    ``}` `    ``// Driver code``    ``public` `static` `void` `main(String args[])``    ``{``        ``GFG g = ``new` `GFG();``        ``String s = ``"abepztydba"``;``        ``int` `K = ``4``;``        ``int` `p = ``110``;` `        ``g.countSubStrings(s, K, p);``    ``}``}` `// This code has been contributed by 29AjayKumar`

## Python3

 `# Python3 implementation of the approach` `# Function that checks if the string``# contain exactly K characters having``# ASCII value greater than p``def` `isValidSubString(r, K, p):` `    ``c ``=` `0``    ``for` `i ``in` `range``(``0``, ``len``(r)):` `        ``# if ASCII value is``        ``# greater than 'p'``        ``if` `ord``(r[i]) > p:``            ``c ``+``=` `1` `    ``# if count of satisfying``    ``# characters is equal to 'K'``    ``# then return true``    ``if` `c ``=``=` `K:``        ``return` `True` `    ``# otherwise return false``    ``else``:``        ``return` `False` `# function to count sub-strings``def` `countSubStrings(s, K, p):` `    ``# length of the string``    ``l ``=` `len``(s)` `    ``# count of sub-strings``    ``count ``=` `0` `    ``# 'i' is the starting``    ``# index for the sub-string``    ``for` `i ``in` `range``(``0``, l):` `        ``# 'j' is the no. of characters``        ``# to include in the sub-string``        ``for` `j ``in` `range``(K, l ``-` `i ``+` `1``):``            ``r ``=` `s[i:i ``+` `j]` `            ``# check if the sub-string``            ``# satisfies the condition``            ``if` `isValidSubString(r, K, p) ``=``=` `True``:``                ``count ``+``=` `1` `    ``print``(count)` `# Driver code``if` `__name__ ``=``=` `"__main__"``:` `    ``s ``=` `"abepztydba"``    ``K, p ``=` `4``, ``110` `    ``countSubStrings(s, K, p)` `# This code is contributed by Rituraj Jain`

## C#

 `// C# implementation of the approach``using` `System;` `class` `GFG {` `    ``// Function that checks if``    ``// the String contain exactly``    ``// K characters having ASCII``    ``// value greater than p``    ``bool` `isValidSubString(String r, ``int` `K, ``int` `p)``    ``{``        ``int` `c = 0;` `        ``for` `(``int` `i = 0; i < r.Length; i++) {` `            ``// if ASCII value is``            ``// greater than 'p'``            ``if` `((``int``)r[i] > p) {``                ``c++;``            ``}``        ``}` `        ``// if count of satisfying``        ``// characters is equal to 'K'``        ``// then return true``        ``if` `(c == K) {``            ``return` `true``;``        ``}` `        ``// otherwise return false``        ``else` `{``            ``return` `false``;``        ``}``    ``}` `    ``// function to count sub-Strings``    ``void` `countSubStrings(String s, ``int` `K, ``int` `p)``    ``{``        ``// length of the String``        ``int` `l = s.Length;` `        ``// count of sub-Strings``        ``int` `count = 0;` `        ``// 'i' is the starting``        ``// index for the sub-String``        ``for` `(``int` `i = 0; i < l; i++) {` `            ``// 'j' is the no. of characters``            ``// to include in the sub-String``            ``for` `(``int` `j = K; (i + j) <= l; j++) {` `                ``String r = s.Substring(i, j);` `                ``// check if the sub-String``                ``// satisfies the condition``                ``if` `(isValidSubString(r, K, p)) {``                    ``count++;``                ``}``            ``}``        ``}``        ``Console.WriteLine(count);``    ``}` `    ``// Driver code``    ``public` `static` `void` `Main(String[] args)``    ``{``        ``GFG g = ``new` `GFG();``        ``String s = ``"abepztydba"``;``        ``int` `K = 4;``        ``int` `p = 110;` `        ``g.countSubStrings(s, K, p);``    ``}``}` `/* This code contributed by PrinciRaj1992 */`

## Javascript

 ``
Output:
`16`

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