message: Update backspace-string-compare.cpp
diff: class Solution {
  public:
  bool backspaceCompare(string S, string T) {
  - int skipS = 0, skipT = 0;
  - for (int i = S.length() - 1, j = T.length() - 1;
  - i >= 0 || j >= 0;
  - --i, --j) {
  - auto x = findNextChar(S, &i, &skipS);
  - auto y = findNextChar(T, &j, &skipT);
  - if (x != y) {
  + for (int i = S.length() - 1, j = T.length() - 1; i >= 0 || j >= 0; --i, --j) {
  + if (findNextChar(S, &i) != findNextChar(T, &j)) {
  return false;
  }
  }
  @@ -18,12 +13,13 @@ public:
  }
  private:
  - char findNextChar(const string& s, int *i, int *skip) {
  + char findNextChar(const string& s, int *i) {
  + int skip = 0;
  for (; *i >= 0; --(*i)) {
  if (s[*i] == '#') {
  - ++(*skip);
  - } else if ((*skip) > 0) {
  - --(*skip);
  + ++skip;
  + } else if (skip > 0) {
  + --skip;
  } else {
  return s[*i];
  }
  