35.search-insert-position.cpp

/*
 * @lc app=leetcode id=35 lang=cpp
 *
 * [35] Search Insert Position
 *
 * https://leetcode.com/problems/search-insert-position/description/
 *
 * algorithms
 * Easy (42.20%)
 * Likes:    9233
 * Dislikes: 456
 * Total Accepted:    1.6M
 * Total Submissions: 3.9M
 * Testcase Example:  '[1,3,5,6]\n5'
 *
 * Given a sorted array of distinct integers and a target value, return the
 * index if the target is found. If not, return the index where it would be if
 * it were inserted in order.
 *
 * You must write an algorithm with O(log n) runtime complexity.
 *
 *
 * Example 1:
 *
 *
 * Input: nums = [1,3,5,6], target = 5
 * Output: 2
 *
 *
 * Example 2:
 *
 *
 * Input: nums = [1,3,5,6], target = 2
 * Output: 1
 *
 *
 * Example 3:
 *
 *
 * Input: nums = [1,3,5,6], target = 7
 * Output: 4
 *
 *
 *
 * Constraints:
 *
 *
 * 1 <= nums.length <= 10^4
 * -10^4 <= nums[i] <= 10^4
 * nums contains distinct values sorted in ascending order.
 * -10^4 <= target <= 10^4
 *
 *
 */

// @lc code=start
class Solution
{
public:
    int searchInsert(vector<int> &nums, int target)
    {
        int i = 0, j = nums.size() - 1;
        for (int k = (i + j) / 2; i <= j; k = (i + j) / 2)
        {
            if (nums[k] == target)
                return k;
            else if (nums[k] < target)
                i = k + 1;
            else
                j = k - 1;
        }
        return i;
    }
};
// @lc code=end