Search Insert Position

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35.Search Insert Position

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:

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Input: nums = [1,3,5,6], target = 5
Output: 2

Example 2:

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Input: nums = [1,3,5,6], target = 2
Output: 1

Example 3:

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Input: nums = [1,3,5,6], target = 7
Output: 4

个人解答：

时间复杂度O(logn)；

空间复杂度O(1)

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int searchInsert(vector<int>& nums, int target) {
    int n = nums.size();
    int left = 0, right = n - 1, ans = n;
    while (left <= right) {
        int mid = left + ((right - left) / 2);
        if (target <= nums[mid]) {
            ans = mid;
            right = mid - 1;
        }
        else {
            left = mid + 1;
        }
    }
    return ans;
}