Update Solution.kt

Author: ThanhNIT

src/main/kotlin/g1001_1100/s1036_escape_a_large_maze/Solution.kt

@@ -8,16 +8,16 @@ class Solution {
         if (blocked.isEmpty()) {
             return true
         }
-        val blocks: MutableSet<Int> = HashSet()
+
+        val blocks = mutableSetOf<Int>()
         for (b in blocked) {
-            if (target[0] * 1000000 + target[1] != b[0] * 1000000 + b[1]) {
-                blocks.add(b[0] * 1000000 + b[1])
+            if (target[0] * 1_000_000 + target[1] != b[0] * 1_000_000 + b[1]) {
+                blocks.add(b[0] * 1_000_000 + b[1])
             }
         }
-        return (
-            dfs(blocks, source, source[0], source[1], HashSet(), target) &&
-                dfs(blocks, target, target[0], target[1], HashSet(), source)
-            )
+
+        return dfs(blocks, source, source[0], source[1], mutableSetOf(), target) &&
+            dfs(blocks, target, target[0], target[1], mutableSetOf(), source)
     }
 
     private fun dfs(
@@ -28,22 +28,25 @@ class Solution {
         visited: MutableSet<Int>,
         target: IntArray,
     ): Boolean {
-        if (i < 0 || j < 0 || i > 999999 || j > 999999 || blocks.contains(i * 1000000 + j) ||
-            visited.contains(i * 1000000 + j)
-        ) {
+        if (i < 0 || j < 0 || i > 999_999 || j > 999_999) {
+            return false
+        }
+        val pos = i * 1_000_000 + j
+        if (blocks.contains(pos) || visited.contains(pos)) {
             return false
         }
         if (i == target[0] && j == target[1]) {
             return true
         }
-        visited.add(i * 1000000 + j)
-        return if (visited.size > blocks.size * (blocks.size + 1)) {
-            true
-        } else {
-            dfs(blocks, start, i + 1, j, visited, target) ||
-                dfs(blocks, start, i - 1, j, visited, target) ||
-                dfs(blocks, start, i, j + 1, visited, target) ||
-                dfs(blocks, start, i, j - 1, visited, target)
+
+        visited.add(pos)
+        if (visited.size > blocks.size * (blocks.size + 1)) {
+            return true
         }
+
+        return dfs(blocks, start, i + 1, j, visited, target) ||
+            dfs(blocks, start, i - 1, j, visited, target) ||
+            dfs(blocks, start, i, j + 1, visited, target) ||
+            dfs(blocks, start, i, j - 1, visited, target)
     }
 }