Question Move a gameobject with a single touch or single keydown input

As a beginner, I want to move a gameobject between two positions smoothly. But I don' know why I have some problems.I tried several codes. One of them is here.When I give a touch input,it just moves a little.I have to press hundereds of times.I will be grateful if you could help me.

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4.  
5. public class PlayerMove : MonoBehaviour
6. {
7.  
8.     [SerializeField] Transform right;
9.     [SerializeField] Transform middle;
10.     [SerializeField] Transform left;
11.     [SerializeField] float t = 2f;
12.     int location = 1; // 0 left,1 middle , 2 right
13.  
14.     private void Update()
15.     {
16.         if (Input.touchCount > 0)
17.         {
18.             if (Input.GetTouch(0).phase == TouchPhase.Began && Input.GetTouch(0).position.x < Screen.width / 2)
19.             {
20.                 DesiredLocation(false);
21.                 Transport(location);
22.             }
23.             if (Input.GetTouch(0).phase == TouchPhase.Began && Input.GetTouch(0).position.x > Screen.width / 2)
24.             {
25.                 DesiredLocation(true);
26.                 Transport(location);
27.             }
28.         }
29.     }
30.     void Transport(int lane)
31.     {
32.         switch (lane)
33.         {
34.             case 0:
35.                 transform.position = Vector3.Lerp(transform.position, left.position, t*Time.deltaTime);
36.                 break;
37.             case 1:
38.                 transform.position = Vector3.Lerp(transform.position, middle.position, t*Time.deltaTime);
39.                 break;
40.             case 2:
41.                 transform.position = Vector3.Lerp(transform.position, right.position, t*Time.deltaTime);
42.                 break;
43.         }
44.     }
45.     void DesiredLocation(bool isRight)
46.     {
47.         location += (isRight) ? 1 : -1;
48.         location = Mathf.Clamp(location, 0, 2);
49.     }