1277. Count Square Submatrices with All Ones

Author: partho-maple

README.md

@@ -764,6 +764,7 @@ BFS, DFS, Dijkstra, Floyd–Warshall, Bellman-Ford, Kruskal, Prim's, Minimum Spa
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 </p>

leetcode.com/swift/DS_ALGO_PRAC.playground/Sources/swift/1277_Count_Square_Submatrices_with_All_Ones.swift

@@ -0,0 +1,28 @@
+import Foundation
+class Solution {
+    func countSquares(_ matrix: [[Int]]) -> Int {
+        let (rows, cols) = (matrix.count, matrix[0].count)
+        guard rows > 0, cols > 0 else {
+            return 0
+        }
+        var dp = matrix
+        var result = 0
+        for i in 0..<rows {
+            for j in 0..<cols {
+                if matrix[i][j] == 1 {
+                    if i == 0 || j == 0 {
+                        result += 1
+                    } else {
+                        var cellValue = 1
+                        if let minNeighbour = [ dp[i][j - 1], dp[i - 1][j - 1], dp[i - 1][j] ].min() {
+                            cellValue += minNeighbour
+                        }
+                        result += cellValue
+                        dp[i][j] = cellValue
+                    }
+                }
+            }
+        }
+        return result
+    }
+}