Convex Polygon(LeetCode 469):

Problem

You are given an array of points on the X-Y plane points where points[i] = [xi, yi]. The points form a polygon when joined sequentially.

Return true if this polygon is convex and false otherwise.

You may assume the polygon formed by given points is always a simple polygon. In other words, we ensure that exactly two edges intersect at each vertex and that edges otherwise don't intersect each other.

 

Example 1:

Input: points = [[0,0],[0,5],[5,5],[5,0]]
Output: true

Example 2:

Input: points = [[0,0],[0,10],[10,10],[10,0],[5,5]]
Output: false

 

Constraints:

  • 3 <= points.length <= 104
  • points[i].length == 2
  • -104 <= xi, yi <= 104
  • All the given points are unique.