LeetCode in Kotlin
593. Valid Square
Medium
Given the coordinates of four points in 2D space p1, p2, p3 and p4, return true if the four points construct a square.
The coordinate of a point pi is represented as [xi, yi]. The input is not given in any order.
A valid square has four equal sides with positive length and four equal angles (90-degree angles).
Example 1:
Input: p1 = [0,0], p2 = [1,1], p3 = [1,0], p4 = [0,1]
Output: true
Example 2:
Input: p1 = [0,0], p2 = [1,1], p3 = [1,0], p4 = [0,12]
Output: false
Example 3:
Input: p1 = [1,0], p2 = [-1,0], p3 = [0,1], p4 = [0,-1]
Output: true
Constraints:
p1.length == p2.length == p3.length == p4.length == 2-104 <= xi, yi <= 104
Solution
class Solution {
fun validSquare(p1: IntArray, p2: IntArray, p3: IntArray, p4: IntArray): Boolean {
val distancesSquared = IntArray(6)
distancesSquared[0] = getDistanceSquared(p1, p2)
distancesSquared[1] = getDistanceSquared(p1, p3)
distancesSquared[2] = getDistanceSquared(p1, p4)
distancesSquared[3] = getDistanceSquared(p2, p3)
distancesSquared[4] = getDistanceSquared(p2, p4)
distancesSquared[5] = getDistanceSquared(p3, p4)
distancesSquared.sort()
if (distancesSquared[0] == 0) {
return false
}
if (distancesSquared[0] != distancesSquared[3]) {
return false
}
return if (distancesSquared[4] != distancesSquared[5]) {
false
} else distancesSquared[5] == 2 * distancesSquared[0]
}
private fun getDistanceSquared(p1: IntArray, p2: IntArray): Int {
val deltaX = p2[0] - p1[0]
val deltaY = p2[1] - p1[1]
return deltaX * deltaX + deltaY * deltaY
}
}