Added codes for 11 April

GeeksForGeeks/April/11-4-24/GFG.java

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+//{ Driver Code Starts
+//Initial Template for Java
+
+import java.io.*;
+import java.util.*;
+
+
+// } Driver Code Ends
+//User function Template for Java
+
+class Solution
+{
+    // function to convert a given Gray equivalent n to Binary equivalent.
+    public static int grayToBinary(int n) 
+    {
+        // Your code here
+        int res = n;
+
+        while (n > 0) 
+        {
+            n >>= 1;
+            res ^= n;
+        }
+
+        return res;
+    }
+}
+
+
+
+//{ Driver Code Starts.
+
+class GFG {
+
+	public static void main (String[] args) {
+		Scanner sc = new Scanner(System.in);
+		int t = sc.nextInt();//testcases
+		while(t-->0){
+		    int n = sc.nextInt();//initializing n
+
+		    Solution obj = new Solution();
+
+		    //calling grayToBinary() function
+		    System.out.println(obj.grayToBinary(n));
+		}
+	}
+}
+
+// } Driver Code Ends

GeeksForGeeks/April/11-4-24/README.md

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+Time complexity - O(logn)
+Space complexity - O(1)

LeetCode/April/11-4-24/README.md

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+Time complexity - O(n)
+Space complexity - O(n)

LeetCode/April/11-4-24/Solution.java

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+class Solution 
+{
+    public String removeKdigits(String num, int k) 
+    {
+        if (num.length() == k)
+            return "0";
+
+        StringBuilder sb = new StringBuilder();
+        LinkedList<Character> stack = new LinkedList<>();
+
+        for (int i = 0; i < num.length(); ++i) 
+        {
+            while (k > 0 && !stack.isEmpty() && stack.getLast() > num.charAt(i)) 
+            {
+                stack.pollLast();
+                --k;
+            }
+            stack.addLast(num.charAt(i));
+        }
+
+        while (k-- > 0)
+            stack.pollLast();
+
+        for (char c : stack) 
+        {
+            if (c == '0' && sb.length() == 0)
+                continue;
+            sb.append(c);
+        }
+
+        return sb.length() == 0 ? "0" : sb.toString();
+    }
+}