如何在不使用Collections.binarySearch的情况下获取ArrayList中int输入的插入点

Question

有方法和arr已经排序......

public int search(ArrayList<Integer> arr, int numberToBeSearched) {
    //Code here
    return //insertion point
}

让我们成为{1,4,7}和numberToBeSearched 2。 return将为1，因为为了维持订单，它将介于1和4之间。

如果不使用Collections.binarySearch，你们怎么会在arr里面获得numberToBeSearched的插入点？

插入点是索引位置所在 该数字需要插入数组列表中，以便维护排序顺序。

Answer 1

        public int search(ArrayList<Integer> arr, int numberToBeSearched) {
            int i=0;
            for (i = 0; i < size(); i++) {
                // if the element you are looking at is smaller than numberToBeSearched, 
                // go to the next element
                if (arr.get(i) < numberToBeSearched) continue;
                // if the element equals numberToBeSearched, return, because we don't duplicates
                if (arr.get(i) == numberToBeSearched) return -1;
                // otherwise, we have found the location of numberToBeSearched
                return i;
            }
            // we looked through all of the elements, and they were all
            // smaller than numberToBeSearched, so the index is  end of the list
            return i;
        }