844.Backspace-String-Compare.js

/*
p1 - Pointer 1
p2 - Pointer 2
*/
var backspaceCompare = function (s, t) {
  let p1 = s.length - 1; //setting P1 starting point
  let p2 = t.length - 1; // setting p2 starting point
  while (p1 >= 0 || p2 >= 0) {
    if (s[p1] === "#" || t[p2] === "#") {
      if (s[p1] === "#") {
        let backCount = 2;

        while (backCount > 0) {
          p1--;
          backCount--;

          if (s[p1] === "#") {
            backCount += 2;
          }
        }
      }
      if (t[p2] === "#") {
        let backCount = 2;

        while (backCount > 0) {
          p2--;
          backCount--;

          if (t[p2] === "#") {
            backCount += 2;
          }
        }
      }
    } else {
      if (s[p1] !== t[p2]) {
        return false;
      } else {
        p1--;
        p2--;
      }
    }
  }
  return true;
};