chore(C): add tower of Hanoi using recursion (#681)

algorithms/C/README.md

@@ -39,6 +39,10 @@
 - [Double Ended Queue using array](queues/double-ended-queue-using-array.c)
 - [Circular Queue using array](queues/circular-queue-using-array.c)
 
+## Recursion
+
+- [Tower of Hanoi](recursion/tower-of-hanoi.c)
+
 ## Sorting
 
 - [Bubble Sort](sorting/bubble-sort.c)

algorithms/C/recursion/tower-of-hanoi.c

@@ -0,0 +1,101 @@
+#include <stdio.h>
+/*
+	*Tower of Hanoi*
+
+	*Rule:
+	
+	1. Only one disk can be moved at a time.
+	2. Each move consists of taking the upper disk from one of the stacks 
+	   and placing it on top of another stack i.e. 
+	   a disk can only be moved if it is the uppermost disk on a stack.
+	3. No disk may be placed on top of a smaller disk.
+
+	* Time Complexity : O(2^n) 
+	* Space Complexity: O(n) 
+*/
+
+
+void towerOfHanoi(int disk, char from, char by, char to)
+{
+	if (disk == 1) // If the number of disks to move is one
+	{
+		printf("Move disk 1 from %c to %c \n", from, to);
+	}
+	else
+	{
+		towerOfHanoi(disk - 1, from, to, by);
+		printf("Move disk %d from %c to %c \n", disk, from, to);
+		towerOfHanoi(disk - 1, by, from, to);
+	}
+
+}
+
+int main()
+{
+	int disk;
+	
+	printf("Enter the number of disks you want : ");
+	scanf("%d", &disk);
+
+	// Move N disks of Tower A to Tower C via Tower B
+	towerOfHanoi(disk, 'A', 'B', 'C');
+	
+	return 0;
+}
+
+/*
+                                Sample
+
+                input             |                     output
+                                  |
+              disk : 3            |             Move disk 1 from A to C
+                                  |             Move disk 2 from A to B
+                                  |             Move disk 1 from C to B
+                                  |             Move disk 3 from A to C
+                                  |             Move disk 1 from B to A
+                                  |             Move disk 2 from B to C
+                                  |             Move disk 1 from A to C
+
+
+---------------------------------------------------------------------------
+
+
+                   **Image illustration for 3 disks**
+
+
+        standby                                         step 1
+
+    A      B      C                             A         B        C
+
+    |      |      |                             |         |        |
+    |      |      |                             |         |        |
+   ###(1)  |      |                             |         |        |
+  #####(2) |      |                           #####       |        |
+_#######(3)|______|__                       _#######______|_______###_
+
+
+
+         step 2                  step 3	                 step 4
+
+    A      B      C        A       B      C        A       B       C
+
+    |      |      |        |       |      |        |       |       |
+    |      |      |        |       |      |        |       |       |
+    |      |      |        |       |      |        |       |       |
+    |      |      |        |      ###     |        |      ###      |
+_#######_#####___###__  #######__#####____|___   __|_____#####__#######__
+
+
+
+         step 5                  step 6	                    step 7
+
+    A      B      C         A      B      C          A        B	       C
+
+    |      |      |         |      |      |          |	      |	       |
+    |      |      |         |      |      |          |        |        |
+    |      |      |         |      |      |          |        |	      ###
+    |      |      |         |      |    #####        |        |	     #####
+___###___#####_#######_	___###_____|___#######_    __|________|_____#######__
+
+
+*/