# Check if the string contains consecutive letters and each letter occurs exactly once

Given string str. The task is to check if the string contains consecutive letters and each letter occurs exactly once.

Examples:

Input: str = “fced”
Output: Yes

The string contains ‘c’, ‘d’, ‘e’ and ‘f’ which are consecutive letters.

Input: str = “xyz”
Output: Yes

Input: str = “abd”
Output: No

The following steps can be followed to solve the problem:

• Sort the given string in ascending order.
• Check if s[i]-s[i-1]==1, for every index i from 1 to n-1.
• If the condition holds for every index, print “Yes”, else print “No”.

Below is the implementation of the above approach:

## C++

 `// C++ program to implement ` `// the above approach ` `#include ` `using` `namespace` `std; ` ` `  `// Function to check if ` `// the condition holds ` `bool` `check(string s) ` `{ ` ` `  `    ``// Get the length of the string ` `    ``int` `l = s.length(); ` ` `  `    ``// sort the given string ` `    ``sort(s.begin(), s.end()); ` ` `  `    ``// Iterate for every index and ` `    ``// check for the condition ` `    ``for` `(``int` `i = 1; i < l; i++) { ` ` `  `        ``// If are not consecutive ` `        ``if` `(s[i] - s[i - 1] != 1) ` `            ``return` `false``; ` `    ``} ` ` `  `    ``return` `true``; ` `} ` ` `  `// Driver code ` `int` `main() ` `{ ` ` `  `    ``// 1st example ` `    ``string str = ``"dcef"``; ` `    ``if` `(check(str)) ` `        ``cout << ``"Yes\n"``; ` `    ``else` `        ``cout << ``"No\n"``; ` ` `  `    ``// 2nd example ` `    ``str = ``"xyza"``; ` ` `  `    ``if` `(check(str)) ` `        ``cout << ``"Yes\n"``; ` `    ``else` `        ``cout << ``"No\n"``; ` ` `  `    ``return` `0; ` `} `

## Java

 `// Java program to implement  ` `// the above approach  ` `import` `java.util.*; ` `class` `GfG {  ` ` `  `// Function to check if  ` `// the condition holds  ` `static` `boolean` `check(``char` `s[])  ` `{  ` ` `  `    ``// Get the length of the string  ` `    ``int` `l = s.length;  ` ` `  `    ``// sort the given string  ` `    ``Arrays.sort(s);  ` ` `  `    ``// Iterate for every index and  ` `    ``// check for the condition  ` `    ``for` `(``int` `i = ``1``; i < l; i++) {  ` ` `  `        ``// If are not consecutive  ` `        ``if` `(s[i] - s[i - ``1``] != ``1``)  ` `            ``return` `false``;  ` `    ``}  ` ` `  `    ``return` `true``;  ` `}  ` ` `  `// Driver code  ` `public` `static` `void` `main(String[] args)  ` `{  ` ` `  `    ``// 1st example  ` `    ``String str = ``"dcef"``;  ` `    ``if` `(check(str.toCharArray()) == ``true``)  ` `        ``System.out.println(``"Yes"``);  ` `    ``else` `        ``System.out.println(``"No"``);  ` ` `  `    ``// 2nd example  ` `    ``String str1 = ``"xyza"``;  ` ` `  `    ``if` `(check(str1.toCharArray()) == ``true``)  ` `        ``System.out.println(``"Yes"``);  ` `    ``else` `        ``System.out.println(``"No"``);  ` ` `  `}  ` `}  `

## Python3

 `# Python3 program to implement  ` `# the above approach  ` ` `  `# Function to check if  ` `# the condition holds  ` `def` `check(s):  ` ` `  `    ``# Get the length of the string  ` `    ``l ``=` `len``(s)  ` ` `  `    ``# sort the given string  ` `    ``s ``=` `''.join(``sorted``(s))  ` ` `  `    ``# Iterate for every index and  ` `    ``# check for the condition  ` `    ``for` `i ``in` `range``(``1``, l):  ` ` `  `        ``# If are not consecutive  ` `        ``if` `ord``(s[i]) ``-` `ord``(s[i ``-` `1``]) !``=` `1``:  ` `            ``return` `False` ` `  `    ``return` `True` ` `  `# Driver code  ` `if` `__name__ ``=``=` `"__main__"``: ` ` `  `    ``# 1st example  ` `    ``string ``=` `"dcef"` `     `  `    ``if` `check(string):  ` `        ``print``(``"Yes"``)  ` `    ``else``: ` `        ``print``(``"No"``)  ` ` `  `    ``# 2nd example  ` `    ``string ``=` `"xyza"` ` `  `    ``if` `check(string):  ` `        ``print``(``"Yes"``)  ` `    ``else``: ` `        ``print``(``"No"``)  ` ` `  `# This code is contributed by Rituraj Jain `

## C#

 `// C# program to implement  ` `// the above approach  ` `using` `System; ` `using` `System.Collections; ` ` `  `class` `GfG  ` `{  ` `     `  `    ``// Function to check if  ` `    ``// the condition holds  ` `    ``static` `bool` `check(``char` `[]s)  ` `    ``{  ` `     `  `        ``// Get the length of the string  ` `        ``int` `l = s.Length;  ` `     `  `        ``// sort the given string  ` `        ``Array.Sort(s);  ` `     `  `        ``// Iterate for every index and  ` `        ``// check for the condition  ` `        ``for` `(``int` `i = 1; i < l; i++) ` `        ``{  ` `     `  `            ``// If are not consecutive  ` `            ``if` `(s[i] - s[i - 1] != 1)  ` `                ``return` `false``;  ` `        ``}  ` `     `  `        ``return` `true``;  ` `    ``}  ` `     `  `    ``// Driver code  ` `    ``public` `static` `void` `Main()  ` `    ``{  ` `     `  `        ``// 1st example  ` `        ``string` `str = ``"dcef"``;  ` `        ``if` `(check(str.ToCharArray()) == ``true``)  ` `            ``Console.WriteLine(``"Yes"``);  ` `        ``else` `            ``Console.WriteLine(``"No"``);  ` `     `  `        ``// 2nd example  ` `        ``String str1 = ``"xyza"``;  ` `     `  `        ``if` `(check(str1.ToCharArray()) == ``true``)  ` `            ``Console.WriteLine(``"Yes"``);  ` `        ``else` `            ``Console.WriteLine(``"No"``);  ` `    ``}  ` `}  ` ` `  `// This code is contributed by Ryuga `

Output:

```Yes
No
```

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