Improved swift

Author: javadev

pom.xml

@@ -5,7 +5,7 @@
     <groupId>com.github.javadev</groupId>
     <artifactId>leetcode-in-all</artifactId>
     <packaging>jar</packaging>
-    <version>1.0</version>
+    <version>1.1</version>
     <name>leetcode-in-all</name>
     <description>104 LeetCode algorithm problem solutions</description>
     <url>https://github.com/javadev/LeetCode-in-All</url>
@@ -88,6 +88,8 @@
                                 <source>src/main/ruby</source>
                                 <source>src/main/scala</source>
                                 <source>src/main/ts</source>
+                                <source>src/main/python</source>
+                                <source>src/main/swift</source>
                             </sources>
                         </configuration>
                     </execution>

src/main/swift/g0101_0200/s0200_number_of_islands/Solution.swift

@@ -1,35 +1,36 @@
-// #Easy #Top_100_Liked_Questions #Top_Interview_Questions #Linked_List #Recursion
-// #Data_Structure_I_Day_8_Linked_List #Algorithm_I_Day_10_Recursion_Backtracking
-// #Level_1_Day_3_Linked_List #Udemy_Linked_List #Big_O_Time_O(N)_Space_O(1)
-// #2024_06_28_Time_4_ms_(89.47%)_Space_16_MB_(24.52%)
+// #Medium #Top_100_Liked_Questions #Top_Interview_Questions #Array #Depth_First_Search
+// #Breadth_First_Search #Matrix #Union_Find
+// #Algorithm_II_Day_6_Breadth_First_Search_Depth_First_Search
+// #Graph_Theory_I_Day_1_Matrix_Related_Problems #Level_1_Day_9_Graph/BFS/DFS #Udemy_Graph
+// #Big_O_Time_O(M*N)_Space_O(M*N) #2024_07_04_Time_152_ms_(70.92%)_Space_19.2_MB_(44.62%)
 
-/**
- * Definition for singly-linked list.
- * public class ListNode {
- *     public var val: Int
- *     public var next: ListNode?
- *     public init() { self.val = 0; self.next = nil; }
- *     public init(_ val: Int) { self.val = val; self.next = nil; }
- *     public init(_ val: Int, _ next: ListNode?) { self.val = val; self.next = next; }
- * }
- */
 class Solution {
-    func reverseList(_ head: ListNode?) -> ListNode? {
-        var prev: ListNode? = nil
-        var curr = head
-        var next = head?.next
+    func numIslands(_ grid: [[Character]]) -> Int {
+        var grid = grid
+        var islands = 0
 
-        while curr != nil {
+        if !grid.isEmpty && !grid[0].isEmpty {
+            for i in 0..<grid.count {
+                for j in 0..<grid[0].count {
+                    if grid[i][j] == "1" {
+                        dfs(&grid, i, j)
+                        islands += 1
+                    }
+                }
+            }
+        }
+        return islands
+    }
 
-            // reverse the current nodes link
-            curr?.next = prev
-            
-            // update variables
-            prev = curr
-            curr = next
-            next = next?.next
+    private func dfs(_ grid: inout [[Character]], _ x: Int, _ y: Int) {
+        if x < 0 || x >= grid.count || y < 0 || y >= grid[0].count || grid[x][y] != "1" {
+            return
         }
 
-        return prev
+        grid[x][y] = "x"
+        dfs(&grid, x + 1, y)
+        dfs(&grid, x - 1, y)
+        dfs(&grid, x, y + 1)
+        dfs(&grid, x, y - 1)
     }
 }

src/main/swift/g0501_0600/s0560_subarray_sum_equals_k/Solution.swift

@@ -3,19 +3,18 @@
 
 class Solution {
     func subarraySum(_ nums: [Int], _ k: Int) -> Int {
-       var result = 0
-    var dict = [Int: Int]()
-    dict[0] = 1
+        var result = 0
+        var dict = [Int: Int]()
+        dict[0] = 1
 
-    var sum = 0
-    for num in nums {
-        sum += num
-        if let val = dict[sum - k] {
-            result += val
+        var sum = 0
+        for num in nums {
+            sum += num
+            if let val = dict[sum - k] {
+                result += val
+            }
+            dict[sum, default: 0] += 1
         }
-        dict[sum, default: 0] += 1
-        }
-
-     return result 
+        return result 
     }
 }