added variable pointer start position

src/turing.rs

@@ -57,6 +57,11 @@ impl TuringMachine {
         self.belt[index] = value;
     }
 
+    pub fn set_pointer(&mut self, index: usize) -> () {
+        // set pointer start position
+        self.pointer = index;
+    }
+
     pub fn set_transition(&mut self, state: u64, value: Value, next_state: u64) -> () {
         // If the State is not in the HashMap, add it
         if self.transitions.get(&state).is_none() {