Merge pull request #6 from rvguradiya/add-generate_gray_code_n_bits

Added problem statement for generating Gray code for n bits

Author: umathomprakash09

problems/general/generate_gray_code_n_bits.md

@@ -0,0 +1,7 @@
+This problem was asked by **Apple**.
+
+[Gray code](https://en.wikipedia.org/wiki/Gray_code) is a binary code where each successive value differ in only one bit, as well as when wrapping around. Gray code is common in hardware so that we don't see temporary spurious values during transitions.
+
+Given a number of bits `n`, generate a possible gray code for it.
+
+For example, for `n = 2`, one gray code would be `[00, 01, 11, 10]`.

solutions/general/generate_gray_code_n_bits/Approach.java

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+public class Approach {
+    public static void generateGrayCode(int n, int bit, String str) {
+        if (n == 1) {
+            System.err.println(str + bit);
+            bit = bit == 1 ? 0 : 1;
+            System.err.println(str + bit);
+            return;
+        }
+        generateGrayCode(n - 1, 0, str + bit);
+        bit = bit == 1 ? 0 : 1;
+        generateGrayCode(n - 1, 1, str + bit);
+    }
+
+    public static void main(String[] args) {
+        generateGrayCode(4, 0, "");
+    }
+}

solutions/general/generate_gray_code_n_bits/approach.js

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+function generateGrayCode(n, bit = 0, s = "") {
+  if (n == 1) {
+    console.log(s + bit);
+    bit = bit == 1 ? 0 : 1;
+    console.log(s + bit);
+    return;
+  }
+  generateGrayCode(n - 1, 0, s + bit);
+  bit = bit == 1 ? 0 : 1;
+  generateGrayCode(n - 1, 1, s + bit);
+}
+
+generateGrayCode(4);

solutions/general/generate_gray_code_n_bits/approach.py

@@ -0,0 +1,13 @@
+def generateGrayCode(n,bit=0,s=''):
+
+    if n == 1:
+        print(s + str(bit))
+        bit = 0 if bit ==1 else 1
+        print(s + str(bit)) 
+        return; 
+    
+    generateGrayCode(n-1,0,s+str(bit))
+    bit = 0 if bit ==1 else 1
+    generateGrayCode(n-1,1,s+str(bit))
+
+generateGrayCode(4)