[프로그래머스]키패드 누르기 (javascript/자바스크립트)

문제

풀이 1

function solution(numbers, hand) {
    var answer = '';
    let key = {
        '1' : [0,0],
        '2' : [0,1],
        '3' : [0,2],
        '4' : [1,0],
        '5' : [1,1],
        '6' : [1,2],
        '7' : [2,0],
        '8' : [2,1],
        '9' : [2,2],
        '*' : [3,0],
        '0' : [3,1],
        '#' : [3,2]
}
    let left = key['*']
    let right = key['#']
    numbers.map((v,i) => {
        let target = key[v]  
        if (v===1 || v=== 4 || v=== 7) {
            answer += 'L' 
            left = target
        }
        else if (v===3 || v=== 6 || v=== 9) {
            answer += 'R'
            right = target
        }
        else {          
            let leftCount = Math.abs(target[0] - left[0]) + Math.abs(target[1] - left[1])
            let rightCount = Math.abs(target[0] - right[0]) + Math.abs(target[1] - right[1])
            
            if (leftCount < rightCount) {
                left = target
                answer += 'L'
            }
            else if (rightCount < leftCount) {
                right = target
                answer += 'R'
            }
            else {
                if (hand === 'left') {
                    left = target
                    answer += 'L'
                }
                else {
                    right =target
                    answer += 'R'
                }
            }
        }
        
    })
    

    return answer;
}

풀이 2

function solution(numbers, hand) {
  hand = hand[0] === "r" ? "R" : "L"
  let position = [1, 4, 4, 4, 3, 3, 3, 2, 2, 2]
  let h = { L: [1, 1], R: [1, 1] }
  return numbers.map(x => {
    if (/[147]/.test(x)) {
      h.L = [position[x], 1]
      return "L"
    }
    if (/[369]/.test(x)) {
      h.R = [position[x], 1]
      return "R"
    }
    let distL = Math.abs(position[x] - h.L[0]) + h.L[1]
    let distR = Math.abs(position[x] - h.R[0]) + h.R[1]
    if (distL === distR) {
      h[hand] = [position[x], 0]
      return hand
    }
    if (distL < distR) {
      h.L = [position[x], 0]
      return "L"
    }
    h.R = [position[x], 0]
    return "R"
  }).join("")
}

풀이 3

function solution(numbers, hand) {
    let answer = '';
    // imagine a grid, and assign each number coordinates
    // by taking 5 being 0,0.
    // If needed, this can also be done programmatically.
    const grid = [[0,-2], [-1,1], [0,1],
                  [1,1], [-1,0], [0,0],
                  [1,0], [-1,-1], [0,-1],
                  [1,-1], [-1,-2], [1,-2]];
    let L = 10; // 10th element of the grid are * and # of the keypad
    let R = 11; // 11th
    let L_steps, R_steps; 
    hand = hand[0].toUpperCase();
    numbers.forEach(el => {
        switch (grid[el][0]){
            case -1:
                answer += "L";
                L = el;
                break;
            case 1:
                answer += "R";
                R = el;
                break;
            case 0:
                L_steps = Math.abs(grid[L][0] - grid[el][0]) + Math.abs(grid[L][1] - grid[el][1]);
                R_steps = Math.abs(grid[R][0] - grid[el][0]) + Math.abs(grid[R][1] - grid[el][1]);
                if(L_steps > R_steps){
                    answer += "R";
                    R = el;
                } else if (L_steps < R_steps){
                    answer += "L";
                    L = el;
                } else {
                    answer += hand;
                    eval(`${hand} = el`); //may affect performance?
                }
        }
    });
    return answer;
}