165-compare-version-numbers.js

/**
 * @param {string} version1
 * @param {string} version2
 * @return {number}
 */
const compareVersion = function(version1, version2) {
  const fa = version1.split(".");
  const sa = version2.split(".");
  const len = Math.max(fa.length, sa.length);
  if (fa.length < len) {
    while (fa.length < len) {
      fa.push("0");
    }
  }
  if (sa.length < len) {
    while (sa.length < len) {
      sa.push("0");
    }
  }
  while (sa.length > 0 && fa.length > 0) {
    let fe = +fa.shift();
    let se = +sa.shift();
    if (fe > se) {
      return 1;
    }
    if (fe < se) {
      return -1;
    }
  }
  return 0;
};