35. Search Insert Position (Easy)

1.問題

• 給予一個sorted list以及target value, 回傳在陣列的位置或是他應該插入的位置

2.想法

• Binary search

3.程式碼

class Solution {
public:
    int searchInsert(vector<int>& nums, int target) {
        int start = 0, end = nums.size()-1;
        if (nums[end] < target) {
            return end + 1;
        }
        if (nums[start] > target) {
            return start;
        }
        while (start <= end) {
            int mid = start + (end - start) /2;
            if (nums[mid] == target ||
                (nums[mid] > target && nums[mid - 1] < target)) {
                return mid;
            }
            if (nums[mid] < target && nums[mid + 1] > target) {
                return mid + 1;
            }
            if (nums[mid] > target) {
                end = mid - 1;
            } else {
                start = mid + 1;
            }
        }
    }
};

4.Performance