Merge pull request #218 from AKS1996/master

Additional files similiar to TheAlgorithms/Python

Author: Christian Bender

Others/GuassLengendre.java

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+import java.lang.Math;
+/*
+ * author: @AKS1996
+ * Guass Legendre Algorithm
+ * ref https://en.wikipedia.org/wiki/Gauss–Legendre_algorithm
+ *
+ */
+
+public class GuassLegendre {
+
+	public static void main(String[] args) {
+		for(int i=1;i<=3;++i)
+			System.out.println(pi(i));
+
+	}
+
+	static double pi(int l){
+		/*
+		 * l: No of loops to run
+		 */
+
+		double a = 1,b=Math.pow(2,-0.5),t=0.25,p=1;
+		for(int i=0;i<l;++i){
+			double temp[] = update(a,b,t,p);
+			a = temp[0];
+			b = temp[1];
+			t = temp[2];
+			p = temp[3];
+		}
+
+		return Math.pow(a+b, 2)/(4*t);
+	}
+
+	static double[] update(double a, double b, double t, double p){
+		double values[] = new double[4];
+		values[0] = (a+b)/2;
+		values[1] = Math.sqrt(a*b);
+		values[2] = t - p*Math.pow(a - values[0],2);
+		values[3] = 2*p;
+
+		return values;
+	}
+
+}

Others/PasswordGen.java

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+import java.util.Collections;
+import java.util.Random;
+import java.util.List;
+import java.util.ArrayList;
+
+/*
+    Creates a random password from ASCII letters
+    Given password length bounds
+    
+    author: AKS1996
+    date: 2017-10-25
+*/
+
+class PasswordGen {
+    public static void main(String args[]){
+	String password = generatePassword(8,16);
+	System.out.print("Password: " + password);
+    }
+	
+    static String generatePassword(int min_length, int max_length){
+        Random random = new Random();
+
+        String upper = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
+        String lower = "abcdefghijklmnopqrstuvwxyz";
+        String numbers = "0123456789";
+        String specialChars = "!@#$%^&*(){}?";
+
+        String allChars = upper+lower+numbers+specialChars;
+
+        List<Character> letters = new ArrayList<Character>();
+        for(char c:allChars.toCharArray())
+            letters.add(c);
+
+        // Inbuilt method to randomly shuffle a elements of a list
+        Collections.shuffle(letters);
+        String password = "";
+
+        // Note that size of the password is also random
+        for(int i = random.nextInt(max_length-min_length) + min_length; i>0; --i) {
+            password += letters.get(random.nextInt(letters.size()));
+        }
+
+        return password;
+    }
+}

data_structures/Stacks/BalancedBrackets.java

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+/*
+
+The nested brackets problem is a problem that determines if a sequence of
+brackets are properly nested.  A sequence of brackets s is considered properly nested
+if any of the following conditions are true:
+	- s is empty
+	- s has the form (U) or [U] or {U} where U is a properly nested string
+	- s has the form VW where V and W are properly nested strings
+For example, the string "()()[()]" is properly nested but "[(()]" is not.
+The function called is_balanced takes as input a string S which is a sequence of brackets and
+returns true if S is nested and false otherwise.
+
+	author: akshay sharma
+	date: 2017-10-17
+*/
+import java.util.Scanner;
+import java.util.Stack;
+import java.util.ArrayList;
+
+class BalancedBrackets {
+
+    static boolean is_balanced(char[] S) {
+        Stack<Character> stack = new Stack<>();
+        String pair = "";
+        for (int i = 0; i < S.length; ++i) {
+            if (S[i] == '(' || S[i] == '{' || S[i] == '[') {
+                stack.push(S[i]);
+            } else if (stack.size() > 0) {
+                if (!pair.equals("[]") && !pair.equals("()") && !pair.equals("{}")) {
+                    return false;
+                }
+            } else {
+                return false;
+            }
+        }
+
+        return stack.isEmpty();
+    }
+
+    static void print(Object a) {
+        System.out.println(a);
+    }
+
+    public static void main(String args[]) {
+        try {
+            Scanner in = new Scanner(System.in);
+            print("Enter sequence of brackets: ");
+            String S = in.nextLine();
+            if (is_balanced(S.toCharArray())) {
+                print(S + " is balanced");
+            } else {
+                print(S + " ain't balanced");
+            }
+            in.close();
+        } catch (Exception e) {
+            e.toString();
+        }
+    }
+}