# Sum of minimum and the maximum difference between two given Strings

Given two strings **S1** and **S2** of the same length. The task is to find the sum of the minimum and the maximum difference between two given strings if you are allowed to replace the character ‘+’ in the strings with any other character.**Note:** If two strings have the same characters at every index, then the difference between them is zero.**Examples:**

Input:S1 = “a+c”, S2 = “++b”Output:4Explanation:

Minimim difference = 1. For minimum difference:

In the string S1 = “a+c”, the “+” can be replaced by “b” thereby making S1 = “abc”

In the string S2 = “++b”, the “++” can be replaced by “ab” thereby making S2 = “abb”

Above, only the 3rd index has a different character. So, the minimum difference = 1

Maximum difference = 1. For maximum difference:

In the string S1 = “a+c”, the “+” can be replaced by “z” thereby making S1 = “azc”

In the string S2 = “++b”, the “++” can be replaced by “bz” thereby making S2 = “bzb”

Above, all the indices has the difference characters. So, the maximum difference = 3

Minimum Difference + Maximum Difference = 1 + 3 = 4Input:S1 = “+++a”, S2 = “+++a”Output:3Explanation:

Minimim difference = 0. For minimum difference:

In the string S1 = “+++a”, the “+++” can be replaced by “aaa” thereby making S1 = “aaaa”

In the string S2 = “+++a”, the “+++” can be replaced by “aaa” thereby making S2 = “aaaa”

Above, all the indices has the same characters. So, the minimum difference = 0

Maximum difference = 3. For maximum difference:

In the string S1 = “+++a”, the “+++” can be replaced by “aaa” thereby making S1 = “aaaa”

In the string S2 = “+++a”, the “+++” can be replaced by “bbb” thereby making S2 = “bbba”

Above, all the indices except the last has the difference characters. So, the maximum difference = 3

Minimum Difference + Maximum Difference = 0 + 3 = 3

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**Approach:**

**Minimum Difference:**In order to get the minimum difference between the strings, all the occurrences of “+” can be replaced by the same character. Therefore, if there is a “+” at any position, then that specific index can be made equal to the other string. Therefore, we only count the number of indices where the character is not “+” in either of the strings and the characters which are not same.**Maximum Difference:**In order to get the maximum difference between the strings, all the occurrences of “+” can be replaced by the different character. Therefore, if there is a “+” at any position, then that specific index can be replaced with a different character other than that present in the second string. Therefore, we count the number of indices where the character is “+” in either of the strings and the characters which are not same.

Below is the implementation of the above approach:

## C++

`// C++ program to find the sum of the` `// minimum and the maximum difference` `// between two given strings` `#include <bits/stdc++.h>` `using` `namespace` `std;` `// Function to find the sum of the` `// minimum and the maximum difference` `// between two given strings` `void` `solve(string a, string b)` `{` ` ` `int` `l = a.length();` ` ` `// Variables to store the minimum` ` ` `// difference and the maximum difference` ` ` `int` `min = 0, max = 0;` ` ` `// Iterate through the length of the string as` ` ` `// both the given strings are of the same length` ` ` `for` `(` `int` `i = 0; i < l; i++) {` ` ` `// For the maximum difference, we can replace` ` ` `// "+" in both the strings with different char` ` ` `if` `(a[i] == ` `'+'` `|| b[i] == ` `'+'` `|| a[i] != b[i])` ` ` `max++;` ` ` `// For the minimum difference, we can replace` ` ` `// "+" in both the strings with the same char` ` ` `if` `(a[i] != ` `'+'` `&& b[i] != ` `'+'` `&& a[i] != b[i])` ` ` `min++;` ` ` `}` ` ` `cout << min + max << endl;` `}` `// Driver code` `int` `main()` `{` ` ` `string s1 = ` `"a+c"` `, s2 = ` `"++b"` `;` ` ` `solve(s1, s2);` ` ` `return` `0;` `}` |

## Java

`// Java program to find the sum of the` `// minimum and the maximum difference` `// between two given Strings` `class` `GFG{` ` ` `// Function to find the sum of the` `// minimum and the maximum difference` `// between two given Strings` `static` `void` `solve(` `char` `[]a, ` `char` `[]b)` `{` ` ` `int` `l = a.length;` ` ` ` ` `// Variables to store the minimum` ` ` `// difference and the maximum difference` ` ` `int` `min = ` `0` `, max = ` `0` `;` ` ` ` ` `// Iterate through the length of the String as` ` ` `// both the given Strings are of the same length` ` ` `for` `(` `int` `i = ` `0` `; i < l; i++) {` ` ` ` ` `// For the maximum difference, we can replace` ` ` `// "+" in both the Strings with different char` ` ` `if` `(a[i] == ` `'+'` `|| b[i] == ` `'+'` `|| a[i] != b[i])` ` ` `max++;` ` ` ` ` `// For the minimum difference, we can replace` ` ` `// "+" in both the Strings with the same char` ` ` `if` `(a[i] != ` `'+'` `&& b[i] != ` `'+'` `&& a[i] != b[i])` ` ` `min++;` ` ` `}` ` ` ` ` `System.out.print(min + max +` `"\n"` `);` `}` ` ` `// Driver code` `public` `static` `void` `main(String[] args)` `{` ` ` `String s1 = ` `"a+c"` `, s2 = ` `"++b"` `;` ` ` `solve(s1.toCharArray(), s2.toCharArray());` `}` `}` `// This code is contributed by Rajput-Ji` |

## Python3

`# Python3 program to find the sum of the` `# minimum and the maximum difference` `# between two given strings` `# Function to find the sum of the` `# minimum and the maximum difference` `# between two given strings` `def` `solve(a, b):` ` ` `l ` `=` `len` `(a)` ` ` `# Variables to store the minimum` ` ` `# difference and the maximum difference` ` ` `min` `=` `0` ` ` `max` `=` `0` ` ` `# Iterate through the length of the as` ` ` `# both the given strings are of the same length` ` ` `for` `i ` `in` `range` `(l):` ` ` `# For the maximum difference, we can replace` ` ` `# "+" in both the strings with different char` ` ` `if` `(a[i] ` `=` `=` `'+'` `or` `b[i] ` `=` `=` `'+'` `or` `a[i] !` `=` `b[i]):` ` ` `max` `+` `=` `1` ` ` `# For the minimum difference, we can replace` ` ` `# "+" in both the strings with the same char` ` ` `if` `(a[i] !` `=` `'+'` `and` `b[i] !` `=` `'+'` `and` `a[i] !` `=` `b[i]):` ` ` `min` `+` `=` `1` ` ` `print` `(` `min` `+` `max` `)` `# Driver code` `if` `__name__ ` `=` `=` `'__main__'` `:` ` ` `s1 ` `=` `"a+c"` ` ` `s2 ` `=` `"++b"` ` ` `solve(s1, s2)` `# This code is contributed by mohit kumar 29 ` |

## C#

`// C# program to find the sum of the` `// minimum and the maximum difference` `// between two given Strings` `using` `System;` `class` `GFG{` ` ` `// Function to find the sum of the` `// minimum and the maximum difference` `// between two given Strings` `static` `void` `solve(` `char` `[]a, ` `char` `[]b)` `{` ` ` `int` `l = a.Length;` ` ` ` ` `// Variables to store the minimum` ` ` `// difference and the maximum difference` ` ` `int` `min = 0, max = 0;` ` ` ` ` `// Iterate through the length of the String as` ` ` `// both the given Strings are of the same length` ` ` `for` `(` `int` `i = 0; i < l; i++) {` ` ` ` ` `// For the maximum difference, we can replace` ` ` `// "+" in both the Strings with different char` ` ` `if` `(a[i] == ` `'+'` `|| b[i] == ` `'+'` `|| a[i] != b[i])` ` ` `max++;` ` ` ` ` `// For the minimum difference, we can replace` ` ` `// "+" in both the Strings with the same char` ` ` `if` `(a[i] != ` `'+'` `&& b[i] != ` `'+'` `&& a[i] != b[i])` ` ` `min++;` ` ` `}` ` ` ` ` `Console.Write(min + max +` `"\n"` `);` `}` ` ` `// Driver code` `public` `static` `void` `Main(String[] args)` `{` ` ` `String s1 = ` `"a+c"` `, s2 = ` `"++b"` `;` ` ` `solve(s1.ToCharArray(), s2.ToCharArray());` `}` `}` `// This code is contributed by Rajput-Ji` |

## Javascript

`<script>` `// Javascript program to find the sum of the` `// minimum and the maximum difference` `// between two given strings` `// Function to find the sum of the` `// minimum and the maximum difference` `// between two given strings` `function` `solve(a, b)` `{` ` ` `var` `l = a.length;` ` ` `// Variables to store the minimum` ` ` `// difference and the maximum difference` ` ` `var` `min = 0, max = 0;` ` ` `// Iterate through the length of the string as` ` ` `// both the given strings are of the same length` ` ` `for` `(` `var` `i = 0; i < l; i++) {` ` ` `// For the maximum difference, we can replace` ` ` `// "+" in both the strings with different char` ` ` `if` `(a[i] == ` `'+'` `|| b[i] == ` `'+'` `|| a[i] != b[i])` ` ` `max++;` ` ` `// For the minimum difference, we can replace` ` ` `// "+" in both the strings with the same char` ` ` `if` `(a[i] != ` `'+'` `&& b[i] != ` `'+'` `&& a[i] != b[i])` ` ` `min++;` ` ` `}` ` ` `document.write(min + max);` `}` `// Driver code` `var` `s1 = ` `"a+c"` `, s2 = ` `"++b"` `;` `solve(s1, s2);` `</script>` |

**Output:**

4

**Time Complexity:** O(N)