806. Number of Lines To Write String

https://leetcode.com/problems/number-of-lines-to-write-string/

JavaScript

/**
 * @param {number[]} widths
 * @param {string} S
 * @return {number[]}
 */
var numberOfLines = function(widths, S) {
  const widthMap = 'abcdefghijklmnopqrstuvwxyz'.split('').reduce((ret, l, i) => {
    ret[l] = widths[i]
    return ret
  }, {})

  let lines = 0
  let units = 0

  S.split('').forEach(l => {
    if (units + widthMap[l] > 100) {
      lines += 1
      units = widthMap[l]
    } else {
      units += widthMap[l]
    }
  })

  return [lines + 1, units]
}

Python

class Solution:

    def numberOfLines(self, widths, S):
        """
        :type widths: List[int]
        :type S: str
        :rtype: List[int]
        """
        lines = 0
        units = 0

        for l in S:
            width = widths[ord(l) - 97]
            if units + width > 100:
                lines += 1
                units = width
            else:
                units += width

        return [lines + 1, units]