Merge pull request #653 from G7-TheKing/master

Added Java implementations of Euler's Totient Function and Tower of Hanoi

Author: matthewsamuel95

Math/TowerofHanoi/toh.java

@@ -0,0 +1,24 @@
+// Java recursive program to solve tower of hanoi puzzle 
+  
+class GFG 
+{ 
+    // Java recursive function to solve tower of hanoi puzzle 
+    static void towerOfHanoi(int n, char from_rod, char to_rod, char aux_rod) 
+    { 
+        if (n == 1) 
+        { 
+            System.out.println("Move disk 1 from rod " +  from_rod + " to rod " + to_rod); 
+            return; 
+        } 
+        towerOfHanoi(n-1, from_rod, aux_rod, to_rod); 
+        System.out.println("Move disk " + n + " from rod " +  from_rod + " to rod " + to_rod); 
+        towerOfHanoi(n-1, aux_rod, to_rod, from_rod); 
+    } 
+      
+    //  Driver method 
+    public static void main(String args[]) 
+    { 
+        int n = 4; // Number of disks 
+        towerOfHanoi(n, 'A', 'C', 'B');  // A, B and C are names of rods 
+    } 
+} 

Math/eulers_totient_function/Java/etf.java

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+// A simple java program to calculate 
+// Euler's Totient Function 
+import java.io.*; 
+  
+class GFG { 
+  
+    // Function to return GCD of a and b 
+    static int gcd(int a, int b) 
+    { 
+        if (a == 0) 
+            return b; 
+        return gcd(b % a, a); 
+    } 
+  
+    // A simple method to evaluate 
+    // Euler Totient Function 
+    static int phi(int n) 
+    { 
+        int result = 1; 
+        for (int i = 2; i < n; i++) 
+            if (gcd(i, n) == 1) 
+                result++; 
+        return result; 
+    } 
+  
+    // Driver code 
+    public static void main(String[] args) 
+    { 
+        int n; 
+  
+        for (n = 1; n <= 10; n++) 
+            System.out.println("phi(" + n + ") = " + phi(n)); 
+    } 
+}