# Find the most valued alphabet in the String

Given a string str, the task is to find the maximum valued alphabet in str. The value of a particular alphabet is defined as the difference in the indices of its last and the first occurrence. If there are multiple such alphabets then find the lexicographically smallest alphabet.

Examples:

Input: str = “abbba”
Output: a
value(‘a’) = 4 – 0 = 4
value(‘b’) = 3 – 1 = 2

Input: str = “bbb”
Output: b

## Recommended: Please try your approach on {IDE} first, before moving on to the solution.

Approach: The idea is to store the first and the last occurrences of each of the alphabets in two auxiliary arrays say first[] and last[]. Now, these two arrays can be used to find the maximum valued alphabet in the given string.

Below is the implementation of the above approach:

## C++

 `// C++ implementation of the approach ` `#include ` `using` `namespace` `std; ` ` `  `const` `int` `MAX = 26; ` ` `  `// Function to return the maximum ` `// valued alphabet ` `char` `maxAlpha(string str, ``int` `len) ` `{ ` ` `  `    ``// To store the first and the last ` `    ``// occurrence of all the characters ` `    ``int` `first[MAX], last[MAX]; ` ` `  `    ``// Set the first and the last occurrence ` `    ``// of all the characters to -1 ` `    ``for` `(``int` `i = 0; i < MAX; i++) { ` `        ``first[i] = -1; ` `        ``last[i] = -1; ` `    ``} ` ` `  `    ``// Update the occurrences of the characters ` `    ``for` `(``int` `i = 0; i < len; i++) { ` ` `  `        ``int` `index = (str[i] - ``'a'``); ` ` `  `        ``// Only set the first occurrence if ` `        ``// it hasn't already been set ` `        ``if` `(first[index] == -1) ` `            ``first[index] = i; ` ` `  `        ``last[index] = i; ` `    ``} ` ` `  `    ``// To store the result ` `    ``int` `ans = -1, maxVal = -1; ` ` `  `    ``// For every alphabet ` `    ``for` `(``int` `i = 0; i < MAX; i++) { ` ` `  `        ``// If current alphabet doesn't appear ` `        ``// in the given string ` `        ``if` `(first[i] == -1) ` `            ``continue``; ` ` `  `        ``// If the current character has ` `        ``// the highest value so far ` `        ``if` `((last[i] - first[i]) > maxVal) { ` `            ``maxVal = last[i] - first[i]; ` `            ``ans = i; ` `        ``} ` `    ``} ` ` `  `    ``return` `(``char``)(ans + ``'a'``); ` `} ` ` `  `// Driver code ` `int` `main() ` `{ ` `    ``string str = ``"abbba"``; ` `    ``int` `len = str.length(); ` ` `  `    ``cout << maxAlpha(str, len); ` ` `  `    ``return` `0; ` `} `

## Java

 `// Java implementation of the approach ` `class` `GFG ` `{ ` ` `  `static` `int` `MAX = ``26``; ` ` `  `// Function to return the maximum ` `// valued alphabet ` `static` `char` `maxAlpha(String str, ``int` `len) ` `{ ` ` `  `    ``// To store the first and the last ` `    ``// occurrence of all the characters ` `    ``int` `[]first = ``new` `int``[MAX]; ` `    ``int` `[]last = ``new` `int``[MAX]; ` ` `  `    ``// Set the first and the last occurrence ` `    ``// of all the characters to -1 ` `    ``for` `(``int` `i = ``0``; i < MAX; i++) ` `    ``{ ` `        ``first[i] = -``1``; ` `        ``last[i] = -``1``; ` `    ``} ` ` `  `    ``// Update the occurrences of the characters ` `    ``for` `(``int` `i = ``0``; i < len; i++)  ` `    ``{ ` ` `  `        ``int` `index = (str.charAt(i) - ``'a'``); ` ` `  `        ``// Only set the first occurrence if ` `        ``// it hasn't already been set ` `        ``if` `(first[index] == -``1``) ` `            ``first[index] = i; ` ` `  `        ``last[index] = i; ` `    ``} ` ` `  `    ``// To store the result ` `    ``int` `ans = -``1``, maxVal = -``1``; ` ` `  `    ``// For every alphabet ` `    ``for` `(``int` `i = ``0``; i < MAX; i++) ` `    ``{ ` ` `  `        ``// If current alphabet doesn't appear ` `        ``// in the given String ` `        ``if` `(first[i] == -``1``) ` `            ``continue``; ` ` `  `        ``// If the current character has ` `        ``// the highest value so far ` `        ``if` `((last[i] - first[i]) > maxVal) ` `        ``{ ` `            ``maxVal = last[i] - first[i]; ` `            ``ans = i; ` `        ``} ` `    ``} ` `    ``return` `(``char``)(ans + ``'a'``); ` `} ` ` `  `// Driver code ` `public` `static` `void` `main(String[] args) ` `{ ` `    ``String str = ``"abbba"``; ` `    ``int` `len = str.length(); ` ` `  `    ``System.out.print(maxAlpha(str, len)); ` `} ` `} ` ` `  `// This code is contributed by 29AjayKumar `

## Python

 `# Python implementation of the approach ` `MAX` `=` `26` ` `  `# Function to return the maximum ` `# valued alphabet ` `def` `maxAlpha(``str``, ``len``): ` ` `  `    ``# To store the first and the last ` `    ``# occurrence of all the characters ` ` `  `    ``# Set the first and the last occurrence ` `    ``# of all the characters to -1 ` `     `  `    ``first ``=` `[``-``1` `for` `x ``in` `range``(``MAX``)] ` `    ``last ``=` `[``-``1` `for` `x ``in` `range``(``MAX``)] ` `     `  `    ``# Update the occurrences of the characters ` `    ``for` `i ``in` `range``(``0``,``len``):  ` ` `  `        ``index ``=` `ord``(``str``[i])``-``97` ` `  `        ``# Only set the first occurrence if ` `        ``# it hasn't already been set ` `        ``if` `(first[index] ``=``=` `-``1``): ` `            ``first[index] ``=` `i ` ` `  `        ``last[index] ``=` `i ` `     `  `    ``# To store the result ` `    ``ans ``=` `-``1` `    ``maxVal ``=` `-``1` ` `  `    ``# For every alphabet ` `    ``for` `i ``in` `range``(``0``,``MAX``): ` ` `  `        ``# If current alphabet doesn't appear ` `        ``# in the given string ` `        ``if` `(first[i] ``=``=` `-``1``): ` `            ``continue` ` `  `        ``# If the current character has ` `        ``# the highest value so far ` `        ``if` `((last[i] ``-` `first[i]) > maxVal): ` `            ``maxVal ``=` `last[i] ``-` `first[i]; ` `            ``ans ``=` `i ` ` `  `    ``return` `chr``(ans ``+` `97``) ` ` `  `# Driver code ` `str` `=` `"abbba"` `len` `=` `len``(``str``) ` ` `  `print``(maxAlpha(``str``, ``len``)) ` ` `  `# This code is contributed by Sanjit_Prasad `

## C#

 `// C# implementation of the approach ` `using` `System; ` ` `  `class` `GFG ` `{ ` `static` `int` `MAX = 26; ` ` `  `// Function to return the maximum ` `// valued alphabet ` `static` `char` `maxAlpha(String str, ``int` `len) ` `{ ` ` `  `    ``// To store the first and the last ` `    ``// occurrence of all the characters ` `    ``int` `[]first = ``new` `int``[MAX]; ` `    ``int` `[]last = ``new` `int``[MAX]; ` ` `  `    ``// Set the first and the last occurrence ` `    ``// of all the characters to -1 ` `    ``for` `(``int` `i = 0; i < MAX; i++) ` `    ``{ ` `        ``first[i] = -1; ` `        ``last[i] = -1; ` `    ``} ` ` `  `    ``// Update the occurrences of the characters ` `    ``for` `(``int` `i = 0; i < len; i++)  ` `    ``{ ` ` `  `        ``int` `index = (str[i] - ``'a'``); ` ` `  `        ``// Only set the first occurrence if ` `        ``// it hasn't already been set ` `        ``if` `(first[index] == -1) ` `            ``first[index] = i; ` ` `  `        ``last[index] = i; ` `    ``} ` ` `  `    ``// To store the result ` `    ``int` `ans = -1, maxVal = -1; ` ` `  `    ``// For every alphabet ` `    ``for` `(``int` `i = 0; i < MAX; i++) ` `    ``{ ` ` `  `        ``// If current alphabet doesn't appear ` `        ``// in the given String ` `        ``if` `(first[i] == -1) ` `            ``continue``; ` ` `  `        ``// If the current character has ` `        ``// the highest value so far ` `        ``if` `((last[i] - first[i]) > maxVal) ` `        ``{ ` `            ``maxVal = last[i] - first[i]; ` `            ``ans = i; ` `        ``} ` `    ``} ` `    ``return` `(``char``)(ans + ``'a'``); ` `} ` ` `  `// Driver code ` `public` `static` `void` `Main(String[] args) ` `{ ` `    ``String str = ``"abbba"``; ` `    ``int` `len = str.Length; ` ` `  `    ``Console.Write(maxAlpha(str, len)); ` `} ` `} ` ` `  `// This code is contributed by Rajput-Ji `

Output:

```a
```

Time Complexity: O(N)

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