# Find if an array contains a string with one mismatch

Given a string and array of strings, find whether the array contains a string with one character difference from the given string. Array may contain strings of different lengths.

Examples:

```Input : str = "banana"
arr[] = {"bana", "apple", "banaba",
bonanzo", "banamf"}
Output :True
Explanation:-There is only a one character difference
between banana and banaba

Input : str = "banana"
arr[] = {"bana", "apple", "banabb", bonanzo",
"banamf"}
Output : False```

We traverse through given string and check for every string in arr. Follow the two steps as given below for every string contained in arr:-

1. Check whether the string contained in arr is of the same length as the target string.
2. If yes, then check if there is only one character mismatch, if yes then return true else return false.

Implementation:

## C++

 `// C++ program to find if given string is present``// with one mismatch.``#include ``using` `namespace` `std;` `bool` `check(vector list, string s)``{``    ``int` `n = (``int``)list.size();` `    ``// If the array is empty    ``    ``if` `(n == 0) ``        ``return` `false``;` `    ``for` `(``int` `i = 0; i < n; i++) {` `        ``// If sizes are same ``        ``if` `(list[i].size() != s.size())``            ``continue``;`` ` `        ``bool` `diff = ``false``;``        ``for` `(``int` `j = 0; j < (``int``)list[i].size(); j++) {` `            ``if` `(list[i][j] != s[j]) {``    ` `                ``// If first mismatch   ``                ``if` `(!diff)``                    ``diff = ``true``;` `                ``// Second mismatch``                ``else` `{``                    ``diff = ``false``;``                    ``break``;``                ``}``            ``}``        ``}` `        ``if` `(diff)``            ``return` `true``;``    ``}` `    ``return` `false``;``}` `// Driver code``int` `main()``{``    ``vector s;``    ``s.push_back(``"bana"``);``    ``s.push_back(``"apple"``);``    ``s.push_back(``"banacb"``);``    ``s.push_back(``"bonanza"``);``    ``s.push_back(``"banamf"``);` `    ``cout << check(s, ``"banana"``);``    ``return` `0;``}`

## Java

 `import` `java.util.*;` `// Java program to find if``// given string is present``// with one mismatch.``class` `GFG``{` `    ``static` `boolean` `check(Vector list, String s) ``    ``{``        ``int` `n = (``int``) list.size();` `        ``// If the array is empty ``        ``if` `(n == ``0``) ``        ``{``            ``return` `false``;``        ``}` `        ``for` `(``int` `i = ``0``; i < n; i++)``        ``{` `            ``// If sizes are same ``            ``if` `(list.get(i).length() != s.length())``            ``{``                ``continue``;``            ``}` `            ``boolean` `diff = ``false``;``            ``for` `(``int` `j = ``0``; j < (``int``) list.get(i).length(); j++) ``            ``{` `                ``if` `(list.get(i).charAt(j) != s.charAt(j)) ``                ``{` `                    ``// If first mismatch ``                    ``if` `(!diff)``                    ``{``                        ``diff = ``true``;``                    ``} ``                    ` `                    ``// Second mismatch``                    ``else``                    ``{``                        ``diff = ``false``;``                        ``break``;``                    ``}``                ``}``            ``}` `            ``if` `(diff) {``                ``return` `true``;``            ``}``        ``}` `        ``return` `false``;``    ``}` `    ``// Driver code``    ``public` `static` `void` `main(String[] args) ``    ``{``        ``Vector s = ``new` `Vector<>();``        ``s.add(``"bana"``);``        ``s.add(``"apple"``);``        ``s.add(``"banacb"``);``        ``s.add(``"bonanza"``);``        ``s.add(``"banamf"``);` `        ``System.out.println(check(s, ``"banana"``) == ``true` `? ``1` `: ``0``);``    ``}``}` `/* This code contributed by PrinciRaj1992 */`

## Python3

 `# Python 3 program to find if given ``# string is present with one mismatch.` `def` `check(``list``, s):``    ``n ``=` `len``(``list``)` `    ``# If the array is empty ``    ``if` `(n ``=``=` `0``): ``        ``return` `False` `    ``for` `i ``in` `range``(``0``, n, ``1``):``        ` `        ``# If sizes are same ``        ``if` `(``len``(``list``[i]) !``=` `len``(s)):``            ``continue` `        ``diff ``=` `False``        ``for` `j ``in` `range``(``0``, ``len``(``list``[i]), ``1``):``            ``if` `(``list``[i][j] !``=` `s[j]):` `                ``# If first mismatch ``                ``if` `(diff ``=``=` `False``):``                    ``diff ``=` `True` `                ``# Second mismatch``                ``else``:``                    ``diff ``=` `False``                    ``break``                ` `        ``if` `(diff):``            ``return` `True` `    ``return` `False` `# Driver code``if` `__name__ ``=``=` `'__main__'``:``    ``s ``=` `[]``    ``s.append(``"bana"``)``    ``s.append(``"apple"``)``    ``s.append(``"banacb"``)``    ``s.append(``"bonanza"``)``    ``s.append(``"banamf"``)` `    ``print``(``int``(check(s, ``"banana"``)))` `# This code is contributed by``# Sahil_shelangia`

## C#

 `// C# program to find if``// given string is present``// with one mismatch.``using` `System;    ``using` `System.Collections.Generic;``public` `class` `GFG``{`` ` `    ``static` `bool` `check(List list, String s) ``    ``{``        ``int` `n = (``int``) list.Count;`` ` `        ``// If the array is empty ``        ``if` `(n == 0) ``        ``{``            ``return` `false``;``        ``}`` ` `        ``for` `(``int` `i = 0; i < n; i++)``        ``{`` ` `            ``// If sizes are same ``            ``if` `(list[i].Length != s.Length)``            ``{``                ``continue``;``            ``}`` ` `            ``bool` `diff = ``false``;``            ``for` `(``int` `j = 0; j < (``int``) list[i].Length; j++) ``            ``{`` ` `                ``if` `(list[i][j] != s[j]) ``                ``{`` ` `                    ``// If first mismatch ``                    ``if` `(!diff)``                    ``{``                        ``diff = ``true``;``                    ``} ``                     ` `                    ``// Second mismatch``                    ``else``                    ``{``                        ``diff = ``false``;``                        ``break``;``                    ``}``                ``}``            ``}`` ` `            ``if` `(diff) {``                ``return` `true``;``            ``}``        ``}`` ` `        ``return` `false``;``    ``}`` ` `    ``// Driver code``    ``public` `static` `void` `Main(String[] args) ``    ``{``        ``List s = ``new` `List();``        ``s.Add(``"bana"``);``        ``s.Add(``"apple"``);``        ``s.Add(``"banacb"``);``        ``s.Add(``"bonanza"``);``        ``s.Add(``"banamf"``);`` ` `        ``Console.WriteLine(check(s, ``"banana"``) == ``true` `? 1 : 0);``    ``}``}``// This code has been contributed by 29AjayKumar`

## Javascript

 ``

Output
`0`

Time complexity: O(n2)
Auxiliary space: O(1)

#### Approach#2: Using sorting

One more approach is to sort the array and then loop through each string in the array. For each string, compare it with the given string character by character and count the number of mismatches. If the count of mismatches is equal to 1, then return True.

#### Algorithm

1. Sort the array
2. Loop through each string in the array
3. Initialize a variable ‘count’ to 0
4. Loop through each character in the string
5. If the character in the given string at index ‘i’ is not equal to the character in the current string at index ‘i’, increment ‘count’ by 1
6. If ‘count’ becomes more than 1 or if the length of the string in the array is less than the length of the given string minus 1, continue to the next string

7. If the length of the string in the array is greater than the length of the given string plus 1, break out of the loop
8. If ‘count’ is equal to 1 and the length of the string in the array is either equal to the length of the given string or the length of the given string minus 1, return True
9. If the loop completes without finding a match, return False

## C++

 `#include ``using` `namespace` `std;` `// Function to check if there is one mismatch between str and any string in arr``bool` `has_one_mismatch(string str, vector arr) {``    ``sort(arr.begin(), arr.end());``    ``for` `(string s : arr) {``        ``int` `count = 0;``        ``int` `i = 0;``        ``while` `(i < s.length() && count <= 1) {``            ``if` `(str[i] != s[i]) {``                ``count += 1;``            ``}``            ``i += 1;``        ``}``        ``if` `(count > 1 || s.length() < str.length()-1) {``            ``continue``;``        ``}``        ``if` `(s.length() > str.length()+1) {``            ``break``;``        ``}``        ``if` `(count == 1 && (s.length() == str.length() || s.length() == str.length()-1)) {``            ``return` `true``;``        ``}``    ``}``    ``return` `false``;``}` `// Driver code``int` `main() {``    ``string str = ``"banana"``;``    ``vector arr = {``"bana"``, ``"apple"``, ``"banaba"``, ``"bonanzo"``, ``"banamf"``};``      ``if``(has_one_mismatch(str, arr)) cout<<``"True"``;``      ``else` `cout<<``"False"``;``}`

## Java

 `import` `java.util.*;` `public` `class` `Main {` `    ``// Function to check if there is one mismatch between``    ``// str and any string in arr``    ``public` `static` `boolean``    ``has_one_mismatch(String str, ArrayList arr)``    ``{``        ``Collections.sort(arr);``        ``for` `(String s : arr) {``            ``int` `count = ``0``;``            ``int` `i = ``0``;``            ``while` `(i < s.length() && count <= ``1``) {``                ``if` `(str.charAt(i) != s.charAt(i)) {``                    ``count += ``1``;``                ``}``                ``i += ``1``;``            ``}``            ``if` `(count > ``1``                ``|| s.length() < str.length() - ``1``) {``                ``continue``;``            ``}``            ``if` `(s.length() > str.length() + ``1``) {``                ``break``;``            ``}``            ``if` `(count == ``1``                ``&& (s.length() == str.length()``                    ``|| s.length() == str.length() - ``1``)) {``                ``return` `true``;``            ``}``        ``}``        ``return` `false``;``    ``}``    ``// driver code``    ``public` `static` `void` `main(String[] args)``    ``{``        ``String str = ``"banana"``;``        ``ArrayList arr = ``new` `ArrayList(``            ``Arrays.asList(``"bana"``, ``"apple"``, ``"banaba"``,``                          ``"bonanzo"``, ``"banamf"``));``        ``if` `(has_one_mismatch(str, arr))``            ``System.out.println(``"True"``);``        ``else``            ``System.out.println(``"False"``);``    ``}``}`

## Python3

 `def` `has_one_mismatch(``str``, arr):``    ``arr.sort()``    ``for` `s ``in` `arr:``        ``count ``=` `0``        ``i ``=` `0``        ``while` `i < ``len``(s) ``and` `count <``=` `1``:``            ``if` `str``[i] !``=` `s[i]:``                ``count ``+``=` `1``            ``i ``+``=` `1``        ``if` `count > ``1` `or` `len``(s) < ``len``(``str``)``-``1``:``            ``continue``        ``if` `len``(s) > ``len``(``str``)``+``1``:``            ``break``        ``if` `count ``=``=` `1` `and` `(``len``(s) ``=``=` `len``(``str``) ``or` `len``(s) ``=``=` `len``(``str``)``-``1``):``            ``return` `True``    ``return` `False` `str` `=` `"banana"``arr``=` `[``"bana"``, ``"apple"``, ``"banaba"``,``                    ``"bonanzo"``, ``"banamf"``]``print``(has_one_mismatch(``str``, arr))`

## C#

 `using` `System;``using` `System.Collections.Generic;``using` `System.Linq;` `class` `Program ``{``  ` `    ``// Function to check if there is one mismatch between``    ``// str and any string in arr``    ``static` `bool` `HasOneMismatch(``string` `str, List<``string``> arr)``    ``{``        ``arr.Sort();``        ``foreach``(``string` `s ``in` `arr)``        ``{``            ``int` `count = 0;``            ``int` `i = 0;``            ``while` `(i < s.Length && count <= 1) {``                ``if` `(str[i] != s[i]) {``                    ``count += 1;``                ``}``                ``i += 1;``            ``}``            ``if` `(count > 1 || s.Length < str.Length - 1) {``                ``continue``;``            ``}``            ``if` `(s.Length > str.Length + 1) {``                ``break``;``            ``}``            ``if` `(count == 1``                ``&& (s.Length == str.Length``                    ``|| s.Length == str.Length - 1)) {``                ``return` `true``;``            ``}``        ``}``        ``return` `false``;``    ``}``    ``// driver code``    ``static` `void` `Main(``string``[] args)``    ``{``        ``string` `str = ``"banana"``;``        ``List<``string``> arr``            ``= ``new` `List<``string``>{ ``"bana"``, ``"apple"``, ``"banaba"``,``                                ``"bonanzo"``, ``"banamf"` `};``        ``if` `(HasOneMismatch(str, arr))``            ``Console.WriteLine(``"True"``);``        ``else``            ``Console.WriteLine(``"False"``);``    ``}``}`

## Javascript

 `// JavaScript code to check if a string has one mismatch` `function` `has_one_mismatch(str, arr) {``    ``arr.sort();``    ``for` `(let s of arr) {``        ``let count = 0;``        ``let i = 0;``        ``while` `(i < s.length && count <= 1) {``            ``if` `(str[i] != s[i]) {``                ``count += 1;``            ``}``            ``i += 1;``        ``}``        ``if` `(count > 1 || s.length < str.length - 1) {``            ``continue``;``        ``}``        ``if` `(s.length > str.length + 1) {``            ``break``;``        ``}``        ``if` `(count == 1 && (s.length == str.length || s.length == str.length - 1)) {``            ``return` `true``;``        ``}``    ``}``    ``return` `false``;``}` `let str = ``"banana"``;``let arr = [``"bana"``, ``"apple"``, ``"banaba"``, ``"bonanzo"``, ``"banamf"``];``console.log(has_one_mismatch(str, arr));`

Output
`True`

Time Complexity: O(nmlog(m)), where n is the length of the array and m is the length of the longest string in the array or the given string
Auxiliary Space: O(1)

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