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 (42.27%)
 * Likes:    9387
 * Dislikes: 461
 * Total Accepted:    1.7M
 * Total Submissions: 4M
 * 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)
    {
        if ( nums.size() == 0)
            return 0;

        int n = nums.size();
        int l = 0, r = n - 1;

        while (l < r)
        {
            int m = l + (r - l) / 2;
            if (nums[m] == target) return m;
            else if (nums[m] > target) r = m;
            else l = m + 1;
        }

        return nums[l] < target ? l + 1 : l;
    }
};
// @lc code=end