class Solution:
    def findReplaceString(self, s: str, indices: List[int], sources: List[str], targets: List[str]) -> str:
        # Each item of this array is a string, not a char! We won't change the size of this array.
        result = list(s)

        for i in range(len(indices)):
            index = indices[i]

            if s[index:index + len(sources[i])] == sources[i]:
                for j in range(index, index + len(sources[i])):
                    if j == index:
                        result[j] = targets[i]
                    else:
                        result[j] = ''

        return ''.join(result)

# @param {String} s
# @param {Integer[]} indices
# @param {String[]} sources
# @param {String[]} targets
# @return {String}
def find_replace_string(s, indices, sources, targets)
  # Each item of this array is a string, not a char! We won't change the size of this array.
  result = s.clone.chars

  indices.each_with_index do |index, i|
    if s[index...index + sources[i].size] == sources[i]
      result[index] = targets[i] # The first one keep the whole targets[i]

      (1...sources[i].size).each do |j|
        result[index + j] = ""
      end
    end
  end

  result.join("")
end