587. Erect the Fence

You are given an array trees where trees[i] = [xi, yi] represents the location of a tree in the garden. Fence the entire garden using the minimum length of rope, as it is expensive. The garden is well-fenced only if all the trees are enclosed. Return the coordinates of trees that are exactly located on the fence perimeter. You may return the answer in any order. Example 1: Input: trees = [[1