LeetCode in Kotlin
1007. Minimum Domino Rotations For Equal Row
Medium
In a row of dominoes, tops[i] and bottoms[i] represent the top and bottom halves of the ith domino. (A domino is a tile with two numbers from 1 to 6 - one on each half of the tile.)
We may rotate the ith domino, so that tops[i] and bottoms[i] swap values.
Return the minimum number of rotations so that all the values in tops are the same, or all the values in bottoms are the same.
If it cannot be done, return -1.
Example 1:
Input: tops = [2,1,2,4,2,2], bottoms = [5,2,6,2,3,2]
Output: 2
Explanation: The first figure represents the dominoes as given by tops and bottoms: before we do any rotations. If we rotate the second and fourth dominoes, we can make every value in the top row equal to 2, as indicated by the second figure.
Example 2:
Input: tops = [3,5,1,2,3], bottoms = [3,6,3,3,4]
Output: -1
Explanation: In this case, it is not possible to rotate the dominoes to make one row of values equal.
Constraints:
2 <= tops.length <= 2 * 104bottoms.length == tops.length1 <= tops[i], bottoms[i] <= 6
Solution
class Solution {
fun minDominoRotations(tops: IntArray, bottoms: IntArray): Int {
val top = tops[0]
var tCount = 0
var bCount = 0
val tSwaps: Int
val bSwaps: Int
var swaps = 0
var valid = true
for (i in tops.indices) {
if (tops[i] == top) {
tCount++
}
if (bottoms[i] == top) {
bCount++
}
if (tops[i] != top && bottoms[i] != top) {
valid = false
swaps = -1
break
}
}
if (valid) {
tSwaps = tops.size - tCount
bSwaps = bottoms.size - bCount
swaps = Math.min(tSwaps, bSwaps)
}
val bottom = bottoms[0]
var tCount1 = 0
var bCount1 = 0
val tSwaps1: Int
val bSwaps1: Int
var swaps1 = 0
var valid1 = true
for (i in bottoms.indices) {
if (tops[i] == bottom) {
tCount1++
}
if (bottoms[i] == bottom) {
bCount1++
}
if (tops[i] != bottom && bottoms[i] != bottom) {
valid1 = false
swaps1 = -1
break
}
}
if (valid1) {
tSwaps1 = tops.size - tCount1
bSwaps1 = bottoms.size - bCount1
swaps1 = Math.min(tSwaps1, bSwaps1)
}
val ans = IntArray(2)
if (swaps1 < swaps) {
ans[0] = swaps1
ans[1] = swaps
} else {
ans[0] = swaps
ans[1] = swaps1
}
return if (ans[0] != -1) {
ans[0]
} else {
ans[1]
}
}
}