Find the direction from given string

Given a string of containing only L’s and R’s which represents left rotation and right rotation respectively. The task is to find the final direction of pivot(i.e N/E/S/W). Let a pivot is pointed towards north(N) in a compass.

Examples:

Input: str = "LLRLRRL"
Output: W
In this input string we rotate pivot to left
when a L char is encountered and right when
R is encountered.

Input: str = "LL"
Output: S

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

Approach:

1. Use a counter that incremented on seeing R and decremented on seeing L.
2. Finally use modulo on counter to get the direction.
3. If count is negative then directions will be different.Check the code for negative as well.

Below is the implementation of above approach:

C++

 // CPP implementation of above approach #include using namespace std;    // Function to find the final direction string findDirection(string s) {     int count = 0;     string d = "";        for (int i = 0; i < s.length(); i++)      {            if (s == '\n')             return NULL;            if (s[i] == 'L')             count--;         else          {             if (s[i] == 'R')                 count++;         }     }        // if count is positive that implies     // resultant is clockwise direction     if (count > 0)      {            if (count % 4 == 0)             d = "N";         else if (count % 4 == 1)             d = "E";         else if (count % 4 == 2)             d = "S";         else if (count % 4 == 3)             d = "W";     }        // if count is negative that implies     // resultant is anti-clockwise direction     if (count < 0)      {            if (count % 4 == 0)             d = "N";         else if (count % 4 == -1)             d = "W";         else if (count % 4 == -2)             d = "S";         else if (count % 4 == -3)             d = "E";     }     return d; }        // Driver code     int main()     {         string s = "LLRLRRL";         cout << (findDirection(s)) << endl;            s = "LL";         cout << (findDirection(s)) << endl;     }    // This code is contributed by  // SURENDRA_GANGWAR

Java

 // Java implementation of above approach import java.util.*;    class GFG {        // Function to find the final direction     static String findDirection(String s)     {         int count = 0;         String d = "";            for (int i = 0; i < s.length(); i++) {                if (s.charAt(0) == '\n')                 return null;                if (s.charAt(i) == 'L')                 count--;             else {                 if (s.charAt(i) == 'R')                     count++;             }         }            // if count is positive that implies         // resultant is clockwise direction         if (count > 0) {                if (count % 4 == 0)                 d = "N";             else if (count % 4 == 1)                 d = "E";             else if (count % 4 == 2)                 d = "S";             else if (count % 4 == 3)                 d = "W";         }            // if count is negative that implies         // resultant is anti-clockwise direction         if (count < 0) {                if (count % 4 == 0)                 d = "N";             else if (count % 4 == -1)                 d = "W";             else if (count % 4 == -2)                 d = "S";             else if (count % 4 == -3)                 d = "E";         }         return d;     }        // Driver code     public static void main(String[] args)     {         String s = "LLRLRRL";         System.out.println(findDirection(s));            s = "LL";         System.out.println(findDirection(s));     } }

C#

 // C# implementation of above approach using System;    class GFG  {    // Function to find the final direction static String findDirection(String s) {     int count = 0;     String d = "";        for (int i = 0; i < s.Length; i++)     {            if (s == '\n')             return null;            if (s[i] == 'L')             count--;         else {             if (s[i] == 'R')                 count++;         }     }        // if count is positive that implies     // resultant is clockwise direction     if (count > 0)     {            if (count % 4 == 0)             d = "N";         else if (count % 4 == 1)             d = "E";         else if (count % 4 == 2)             d = "S";         else if (count % 4 == 3)             d = "W";     }        // if count is negative that implies     // resultant is anti-clockwise direction     if (count < 0)     {            if (count % 4 == 0)             d = "N";         else if (count % 4 == -1)             d = "W";         else if (count % 4 == -2)             d = "S";         else if (count % 4 == -3)             d = "E";     }     return d; }    // Driver code public static void Main() {     String s = "LLRLRRL";     Console.WriteLine(findDirection(s));        s = "LL";     Console.WriteLine(findDirection(s)); } }    // This code is contributed by Shashank

PHP

 0)      {         if (\$count % 4 == 0)             \$d = "N";         else if (\$count % 4 == 1)             \$d = "E";         else if (\$count % 4 == 2)             \$d = "S";         else if (\$count % 4 == 3)             \$d = "W";     }            // if count is negative that      // implies resultant is      // anti-clockwise direction     if (\$count < 0)      {         if (\$count % 4 == 0)             \$d = "N";         else if (\$count % 4 == -1)             \$d = "W";         else if (\$count % 4 == -2)             \$d = "S";         else if (\$count % 4 == -3)             \$d = "E";     }     return \$d; }    // Driver code \$s = "LLRLRRL"; echo findDirection(\$s)."\n";    \$s = "LL"; echo findDirection(\$s)."\n";    // This code is contributed // by ChitraNayal     ?>

Output:

W
S

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