LuckyNumbersInMatrix1380.kt

package easy

/*
Given a m * n matrix of distinct numbers, return all lucky numbers in the matrix in any order.

A lucky number is an element of the matrix such that it is the minimum element in its row and maximum in its column.

Example 1:

Input: matrix = [[3,7,8],[9,11,13],[15,16,17]]
Output: [15]
Explanation: 15 is the only lucky number since it is the minimum in its row and the maximum in its column
Example 2:

Input: matrix = [[1,10,4,2],[9,3,8,7],[15,16,17,12]]
Output: [12]
Explanation: 12 is the only lucky number since it is the minimum in its row and the maximum in its column.
Example 3:

Input: matrix = [[7,8],[1,2]]
Output: [7]
 */
fun luckyNumbers (matrix: Array<IntArray>): List<Int> {
 val result= arrayListOf<Int>()
 matrix.forEach {row->
  var minimum=Int.MAX_VALUE
  var minimumIndex=-1
  row.forEachIndexed{i,v->
   if(v < minimum) {
    minimum = v
    minimumIndex=i
   }
  }
  var max=Int.MIN_VALUE
  for(i in matrix.indices)
  {
   if(matrix[i][minimumIndex] > max)
   {
    max=matrix[i][minimumIndex]
   }
  }
  if(minimum==max)
   result.add(minimum)
 }
 return result

}