From 36a0c63b542be5eeb614f4cb25ffb767e068deba Mon Sep 17 00:00:00 2001
From: Lanre Adedara <lanre.adedara@shara.co>
Date: Thu, 16 May 2024 07:36:41 +0100
Subject: [PATCH] Swift Implementation for LCCI 17.24

---
 lcci/17.24.Max Submatrix/README.md      | 43 +++++++++++++++++++++++++
 lcci/17.24.Max Submatrix/README_EN.md   | 43 +++++++++++++++++++++++++
 lcci/17.24.Max Submatrix/Solution.swift | 40 +++++++++++++++++++++++
 3 files changed, 126 insertions(+)
 create mode 100644 lcci/17.24.Max Submatrix/Solution.swift

diff --git a/lcci/17.24.Max Submatrix/README.md b/lcci/17.24.Max Submatrix/README.md
index c87ef19fb7c47..ace63531dab21 100644
--- a/lcci/17.24.Max Submatrix/README.md	
+++ b/lcci/17.24.Max Submatrix/README.md	
@@ -190,6 +190,49 @@ func getMaxMatrix(matrix [][]int) []int {
 }
 ```
 
+```swift
+class Solution {
+    func getMaxMatrix(_ matrix: [[Int]]) -> [Int] {
+        let m = matrix.count, n = matrix[0].count
+        var s = Array(repeating: Array(repeating: 0, count: n), count: m + 1)
+        
+        for i in 0..<m {
+            for j in 0..<n {
+                s[i + 1][j] = s[i][j] + matrix[i][j]
+            }
+        }
+        
+        var mx = matrix[0][0]
+        var ans = [0, 0, 0, 0]
+        
+        for i1 in 0..<m {
+            for i2 in i1..<m {
+                var nums = [Int](repeating: 0, count: n)
+                for j in 0..<n {
+                    nums[j] = s[i2 + 1][j] - s[i1][j]
+                }
+                
+                var start = 0
+                var f = nums[0]
+                for j in 1..<n {
+                    if f > 0 {
+                        f += nums[j]
+                    } else {
+                        f = nums[j]
+                        start = j
+                    }
+                    if f > mx {
+                        mx = f
+                        ans = [i1, start, i2, j]
+                    }
+                }
+            }
+        }
+        return ans
+    }
+}
+```
+
 <!-- tabs:end -->
 
 <!-- end -->
diff --git a/lcci/17.24.Max Submatrix/README_EN.md b/lcci/17.24.Max Submatrix/README_EN.md
index 9275c03550032..d88832c366e8b 100644
--- a/lcci/17.24.Max Submatrix/README_EN.md	
+++ b/lcci/17.24.Max Submatrix/README_EN.md	
@@ -195,6 +195,49 @@ func getMaxMatrix(matrix [][]int) []int {
 }
 ```
 
+```swift
+class Solution {
+    func getMaxMatrix(_ matrix: [[Int]]) -> [Int] {
+        let m = matrix.count, n = matrix[0].count
+        var s = Array(repeating: Array(repeating: 0, count: n), count: m + 1)
+        
+        for i in 0..<m {
+            for j in 0..<n {
+                s[i + 1][j] = s[i][j] + matrix[i][j]
+            }
+        }
+        
+        var mx = matrix[0][0]
+        var ans = [0, 0, 0, 0]
+        
+        for i1 in 0..<m {
+            for i2 in i1..<m {
+                var nums = [Int](repeating: 0, count: n)
+                for j in 0..<n {
+                    nums[j] = s[i2 + 1][j] - s[i1][j]
+                }
+                
+                var start = 0
+                var f = nums[0]
+                for j in 1..<n {
+                    if f > 0 {
+                        f += nums[j]
+                    } else {
+                        f = nums[j]
+                        start = j
+                    }
+                    if f > mx {
+                        mx = f
+                        ans = [i1, start, i2, j]
+                    }
+                }
+            }
+        }
+        return ans
+    }
+}
+```
+
 <!-- tabs:end -->
 
 <!-- end -->
diff --git a/lcci/17.24.Max Submatrix/Solution.swift b/lcci/17.24.Max Submatrix/Solution.swift
new file mode 100644
index 0000000000000..b13b651ddf02c
--- /dev/null
+++ b/lcci/17.24.Max Submatrix/Solution.swift	
@@ -0,0 +1,40 @@
+class Solution {
+    func getMaxMatrix(_ matrix: [[Int]]) -> [Int] {
+        let m = matrix.count, n = matrix[0].count
+        var s = Array(repeating: Array(repeating: 0, count: n), count: m + 1)
+        
+        for i in 0..<m {
+            for j in 0..<n {
+                s[i + 1][j] = s[i][j] + matrix[i][j]
+            }
+        }
+        
+        var mx = matrix[0][0]
+        var ans = [0, 0, 0, 0]
+        
+        for i1 in 0..<m {
+            for i2 in i1..<m {
+                var nums = [Int](repeating: 0, count: n)
+                for j in 0..<n {
+                    nums[j] = s[i2 + 1][j] - s[i1][j]
+                }
+                
+                var start = 0
+                var f = nums[0]
+                for j in 1..<n {
+                    if f > 0 {
+                        f += nums[j]
+                    } else {
+                        f = nums[j]
+                        start = j
+                    }
+                    if f > mx {
+                        mx = f
+                        ans = [i1, start, i2, j]
+                    }
+                }
+            }
+        }
+        return ans
+    }
+}
\ No newline at end of file