35. 找出插入的位置 Search Insert Position

Given a sorted array 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 may assume no duplicates in the array.

Here are few examples.
[1,3,5,6], 5 → 2
[1,3,5,6], 2 → 1
[1,3,5,6], 7 → 4
[1,3,5,6], 0 → 0

    public int SearchInsert(int[] nums, int target) {
        for (int i = 0; i < nums.Length; i++)
        {
            if (nums[i] >= target)
            {
                return i;
            }
        }
        return nums.Length;
    }

既然是已排序的数组，可以用二分法优化

public class Solution {
    public int SearchInsert(int[] nums, int target) {
		int l = 0, r = nums.Length - 1, m;
		while (l <= r) {
			m = (l + r) / 2;
			if (nums[m] == target) {
				return m;
			}else if (nums[m] > target) {
				r = m - 1;
			}else if (nums[m] < target) {
				l = m + 1;
			}
		}
		return l;
    }
}

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