- Add: Max Area of Island

Author: BNSC1

LeetCode/695. Max Area of Island.kt

@@ -0,0 +1,44 @@
+class Solution {
+    fun maxAreaOfIsland(g: Array<IntArray>): Int {
+        val rows = g.size
+        val cols = g[0].size
+        val dirs = intArrayOf(-1,0,1,0,-1)
+
+        var res = 0
+        val visit = HashSet<Pair<Int,Int>>()
+        val q = LinkedList<Pair<Int,Int>>()
+        fun count(): Int {
+            var res = 0
+            while (q.isNotEmpty()) {
+                res++
+                val coord = q.poll()
+                for (d in 0 until 4) {
+                    val nr = coord.first + dirs[d]
+                    val nc = coord.second + dirs[d+1]
+                    val newCoord = nr to nc
+                    if (nr in 0 until rows &&
+                        nc in 0 until cols &&
+                        newCoord !in visit &&
+                        g[nr][nc] == 1) {
+                            q.add(newCoord)
+                            visit.add(newCoord)
+                        }
+                }
+            }
+            return res
+        }
+
+        repeat(rows) { r ->
+            repeat(cols) { c ->
+                val coord = r to c
+                if (coord !in visit &&
+                    g[r][c] == 1) {
+                        q.add(coord)
+                        visit.add(coord)
+                        res = maxOf(res, count())
+                    }
+            }
+        }
+        return res
+    }
+}