leetcode-278 第一个错误的版本

/**
 * Definition for isBadVersion()
 *
 * @param {integer} version number
 * @return {boolean} whether the version is bad
 * isBadVersion = function(version) {
 *     ...
 * };
 */

/**
 * @param {function} isBadVersion()
 * @return {function}
 */
var solution = function (isBadVersion) {
  /**
 * @param {integer} n Total versions
 * @return {integer} The first bad version
 */
  return function (n) {
    // 二分
    let left = 1,
      right = n;
    // left === right
    // 目的是找到最先出现的isBadVersion为true
    while (left < right) {
      const mid = Math.floor((left + right) / 2);
      if (isBadVersion(mid)) {
        right = mid;
      } else {
        left = mid + 1;
      }
    }
    return left;
  };
};
// 1 2 3 4 5
// false false false true true