codewars042: 老式手機多點擊鍵盤文本輸入

Multi-tap Keypad Text Entry on an Old Mobile Phone

Solution:

import java.util.*;
public class Keypad {
	private static Character[][][] arr = new Character[4][3][];
	private static Map<Character, Integer> map = new HashMap<Character, Integer>();
	static {
		arr[0][0] = new Character[] { '1' };
		arr[0][1] = new Character[] { 'A', 'B', 'C', '2' };
		arr[0][2] = new Character[] { 'D', 'E', 'F', '3' };
		arr[1][0] = new Character[] { 'G', 'H', 'I', '4' };
		arr[1][1] = new Character[] { 'J', 'K', 'L', '5' };
		arr[1][2] = new Character[] { 'M', 'N', 'O', '6' };
		arr[2][0] = new Character[] { 'P', 'Q', 'R', 'S', '7' };
		arr[2][1] = new Character[] { 'T', 'U', 'V', '8' };
		arr[2][2] = new Character[] { 'W', 'X', 'Y', 'Z', '9' };
		arr[3][0] = new Character[] { '*' };
		arr[3][1] = new Character[] { ' ', '0' };
		arr[3][2] = new Character[] { '#' };

		for (int i = 0; i < 4; i++) {
			for (int j = 0; j < 3; j++) {
				for (int k = 0; k < arr[i][j].length; k++) {
					map.put(arr[i][j][k], k + 1);
				}
			}

		}
	}

  public static int presses(String phrase) {

		int sum = 0;
		for (char x : phrase.toUpperCase().toCharArray()) {
			if (map.containsKey(x)) {
				sum += map.get(x);
			}
		}
		return sum;
	    
  }
}

Example Tests:

import static org.junit.Assert.*;
import org.junit.Test;

public class KeypadTest {
    @Test
    public void simpleTest() {
      assertEquals(9, Keypad.presses("LOL"));
      assertEquals(13, Keypad.presses("HOW R U"));
    }
}