Diagonal traversal and diagonal sort in a matrix

Author: HimanshuGarg701

Matrix/DiagonalTraversal.kt

@@ -0,0 +1,94 @@
+package Matrix
+import java.util.*
+class DiagonalTraversal {
+    var map = mutableMapOf<Int, ArrayList<Int>>()
+    fun printTraversal(matrix : Array<Array<Int>>) : Array<Array<Int>>{
+        println("-----------PRINTING THE MATRIX DIAGONALLY---------------------")
+        var index = 0
+        for(i in 0..matrix.size-1){
+            var j : Int = i
+            var k : Int = 0
+            var list = arrayListOf<Int>()
+            while(k < matrix[0].size && j>=0){
+                print("${matrix[j][k]}    ")
+                list.add(matrix[j][k])
+                k++
+                j--
+            }
+            Collections.sort(list)
+            map.put(index, list)
+            index++
+            println()
+        }
+
+        for(i in 1..matrix[0].size-1){
+            var j = i
+            var k = matrix.size-1
+            var list = arrayListOf<Int>()
+            while(k>=0 && j<matrix.size){
+                print("${matrix[k][j]}    ")
+                list.add(matrix[k][j])
+                k--
+                j++
+            }
+            Collections.sort(list)
+            map.put(index, list)
+            index++
+            println()
+        }
+        return changeToDiagonalSort(matrix)
+    }
+    // After the above function, we have all the sorted elements diagonally in map with value of arrayList
+
+    private fun changeToDiagonalSort(matrix : Array<Array<Int>>) : Array<Array<Int>>{
+        var index = 0
+        for(i in 0..matrix.size-1){
+            var j = i
+            var k = 0
+            var arrIndex = 0
+            while(k <matrix[0].size && j>=0){
+                matrix[j][k] = map.get(index)!!.get(arrIndex)
+                arrIndex++
+                k++
+                j--
+            }
+            index++
+        }
+        for(i in 1..matrix[0].size-1) {
+            var j = i
+            var k = matrix.size - 1
+            var arrIndex = 0
+            while (k >= 0 && j < matrix.size) {
+                matrix[k][j] = map.get(index)!!.get(arrIndex)
+                arrIndex++
+                k--
+                j++
+            }
+            index++
+        }
+        return matrix
+    }
+}
+
+fun main(args : Array<String>){
+    val matrix = arrayOf(
+                    arrayOf(1,2,1,6,5),
+                    arrayOf(1,4,9,2,3),
+                    arrayOf(9,5,2,7,1),
+                    arrayOf(8,1,6,2,3),
+                    arrayOf(9,3,9,7,11)
+                )
+
+    val obj = DiagonalTraversal()
+
+    var sortedResult = obj.printTraversal(matrix)
+
+    println()
+    println("---------------------DIAGONALLY SORTED MATRIX------------------------\n")
+    for(i in 0..matrix.size-1){
+        for(j in 0..matrix[i].size-1){
+            print("${matrix[i][j]}    ")
+        }
+        println()
+    }
+}