no message

Author: partho-maple

leetcode.com/swift/DS_ALGO_PRAC.playground/Contents.swift

@@ -1,39 +1,39 @@
 import Foundation
-class Solution {
-    func minimumEffortPath(_ heights: [[Int]]) -> Int {
-        guard !heights.isEmpty, !heights[0].isEmpty else {
-            return 0
-        }
-        
-        var visited = Set<String>()
-        visited.insert("0-0")
-        var (path, minPath) = ([heights[0][0]], heights[0][0])
-        
-        minimumEffortPathDFSHelper(heights, path, &minPath, 0, 0, &visited)
-        return minPath
-    }
-    
-    func minimumEffortPathDFSHelper(_ heights: [[Int]], _ path: [Int], _ minPath: inout Int, _ currentX: Int, _ currentY: Int, _ visited: inout Set<String>) {
-        print("currentX: \(currentX), currentY: \(currentY)")
-        if currentX == heights.count - 1 && currentY == heights[0].count - 1 {
-            minPath = min(minPath, path.max()!)
-            print("path: \(path)")
-            return
-        }
-        print("------")
-        for neighbor in [(-1,0),(0,1),(1,0),(0,-1)] {
-            var (newX, newY) = (currentX + neighbor.0, currentY + neighbor.1)
-            if newX >= 0 && newX < heights.count && newY >= 0 && newY < heights[newX].count && !visited.contains("\(newX)-\(newY)") {
-                var currVal = heights[newX][newY]
-                var prevVal = heights[currentX][currentY]
-                
-                visited.insert("\(newX)-\(newY)")
-                minimumEffortPathDFSHelper(heights, path + [abs(prevVal - currVal)], &minPath, newX, newY, &visited)
-                visited.remove("\(newX)-\(newY)")
-            }
-        }
-    }
-}
+//class Solution {
+//    func minimumEffortPath(_ heights: [[Int]]) -> Int {
+//        guard !heights.isEmpty, !heights[0].isEmpty else {
+//            return 0
+//        }
+//
+//        var visited = Set<String>()
+//        visited.insert("0-0")
+//        var (path, minPath) = ([heights[0][0]], heights[0][0])
+//
+//        minimumEffortPathDFSHelper(heights, path, &minPath, 0, 0, &visited)
+//        return minPath
+//    }
+//
+//    func minimumEffortPathDFSHelper(_ heights: [[Int]], _ path: [Int], _ minPath: inout Int, _ currentX: Int, _ currentY: Int, _ visited: inout Set<String>) {
+//        print("currentX: \(currentX), currentY: \(currentY)")
+//        if currentX == heights.count - 1 && currentY == heights[0].count - 1 {
+//            minPath = min(minPath, path.max()!)
+//            print("path: \(path)")
+//            return
+//        }
+//        print("------")
+//        for neighbor in [(-1,0),(0,1),(1,0),(0,-1)] {
+//            var (newX, newY) = (currentX + neighbor.0, currentY + neighbor.1)
+//            if newX >= 0 && newX < heights.count && newY >= 0 && newY < heights[newX].count && !visited.contains("\(newX)-\(newY)") {
+//                var currVal = heights[newX][newY]
+//                var prevVal = heights[currentX][currentY]
+//
+//                visited.insert("\(newX)-\(newY)")
+//                minimumEffortPathDFSHelper(heights, path + [abs(prevVal - currVal)], &minPath, newX, newY, &visited)
+//                visited.remove("\(newX)-\(newY)")
+//            }
+//        }
+//    }
+//}
 
 /*
  [
@@ -43,3 +43,38 @@ class Solution {
  [1,2,1,2,1],
  [1,1,1,2,1]]
  */
+
+
+
+class Solution {
+    func numSubmat(_ mat: [[Int]]) -> Int {
+        guard !mat.isEmpty && !mat.first?.isEmpty else {
+            return 0
+        }
+        var dp = Array(repeating: Array(repeating: 0, count: mat.first?.count + 1), count: mat.count + 1)
+        var numSubmat = 0
+        for i in 1...mat.count {
+            for j in 1...mat.first?.count {
+                if mat[i - 1][j - 1] == 1 {
+                    var currentCount = 0
+                    if dp[i - 1][j] == 1 {
+                        currentCount += dp[i - 1][j]
+                        currentCount += 1
+                    }
+                    if dp[i - 1][j - 1] == 1 {
+                        currentCount += dp[i - 1][j - 1]
+                        currentCount += 1
+                    }
+                    if dp[i][j - 1] == 1 {
+                        currentCount += dp[i][j - 1]
+                        currentCount += 1
+                    }
+                    
+                    dp[i][j] = currentCount
+                    numSubmat = max(numSubmat, dp[i][j])
+                }
+            }
+        }
+        return currentCount
+    }
+}