https://leetcode-cn.com/problems/search-insert-position/

    1. function searchInsert(nums: number[], target: number): number {
    2.   let left = 0, right = nums.length - 1, mid = 0;
    3.   while (left <= right) {
    4.     mid = (left + right) >>> 1;
    5.     if (target === nums[mid]) {
    6.       return mid;
    7.     } else if (target < nums[mid]) {
    8.       right = mid -1;
    9.     } else {
    10.       left = mid + 1;
    11.     }
    12.   }
    13.   return left;
    14. }

    在线demo

    // 下标
let cursor = 0;
// hooks 存放
let hooks:any = [];
function useCallback<T>(callback: T, deps: React.DependencyList): T {
  hooks[cursor] = hooks[cursor] || [callback, deps];
  const [lastCallBack, lastDeps] = hooks[cursor];
  const hasChanged = !deps.every((el, i) => el === lastDeps[i]);
  // 依赖发生改变，赋新的值
  if (hasChanged) {
    hooks[cursor++] = [callback, deps];
    return callback;
  }
  cursor++;
  return lastCallBack;
}