[leetCode/JS] 6. Zigzag Conversion

난이도 [ 🤔 ] Medium

문제 설명

The string "PAYPALISHIRING" is written in a zigzag pattern on a given number of rows like this: (you may want to display this pattern in a fixed font for better legibility)

P A H N
A P L S I I G
Y I R

And then read line by line: "PAHNAPLSIIGYIR"

Write the code that will take a string and make this conversion given a number of rows:

string convert(string s, int numRows);

 

입출력 예

Example 1:

Input: s = "PAYPALISHIRING", numRows = 3
Output: "PAHNAPLSIIGYIR"

Example 2:

Input: s = "PAYPALISHIRING", numRows = 4
Output: "PINALSIGYAHRPI"

Explanation:
P I N
A L S I G
Y A H R
P I

Example 3:

Input: s = "A", numRows = 1
Output: "A"

 

Constraints

• 1 <= s.length <= 1000
• s consists of English letters (lower-case and upper-case), ',' and '.'.
• 1 <= numRows <= 1000

---

내 솔루션

• 입력값과 출력사이에 어떤 법칙이 있는지 찾아봤는데 없어보여서 그냥 퓸

/**
 * @param {string} s
 * @param {number} numRows
 * @return {string}
 */
var convert = function(s, numRows) {
  const arr = []
  let isUp = true
  for(let i = 0, numRow = 0; i < s.length; i ++) {
    if(!arr[numRow]) arr[numRow] = []
    arr[numRow].push(s[i])
    
    numRow = isUp ? numRow + 1 : numRow - 1;
    if(numRow === numRows-1 || numRow === 0) isUp = !isUp
  }
  
  return arr.flat().join('')
};

 

감상평