Leetcode 1779. Find Nearest Point That Has the Same X or Y Coord

You are given two integers, x and y, 

which represent your current location on a Cartesian grid: (x, y).

You are also given an array points where each points[i] = [ai, bi] 

represents that a point exists at (ai, bi). 

A point is valid if it shares the same x-coordinate or the same y-coordinate as your location.

Return the index (0-indexed) of the valid point with the smallest Manhattan 

distance from your current location.

If there are multiple, return the valid point with the smallest index.

If there are no valid points, return -1.

The Manhattan distance between two points (x1, y1) and (x2, y2) is abs(x1 - x2) + abs(y1 - y2).

Example 1:

Input: x = 3, y = 4, points = [[1,2],[3,1],[2,4],[2,3],[4,4]]

Output: 2

Explanation: Of all the points, only [3,1], [2,4] and [4,4] are valid. 

Of the valid points, [2,4] and [4,4] have the smallest Manhattan distance

from your current location, with a distance of 1. [2,4] has the smallest index, 

so return 2.

Example 2:

Input: x = 3, y = 4, points = [[3,4]]

Output: 0

Explanation: The answer is allowed to be on the same location as your current location.

Example 3:

Input: x = 3, y = 4, points = [[2,3]]

Output: -1

Explanation: There are no valid points.

easy 题目，先确认数据是否是有效的，然后再计算到位置点的曼哈顿距离，保留一个最小值，然后返回即可。

Constraints:

• 1 <= points.length <= 104

• points[i].length == 2

• 1 <= x, y, ai, bi <= 104

Runtime: 2 ms, faster than 64.54% of Java online submissions for Find Nearest Point That Has the Same X or Y Coordinate.

Memory Usage: 50.7 MB, less than 12.67% of Java online submissions for Find Nearest Point That Has the Same X or Y Coordinate.