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Boudhayan Biswas
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Add remove islands
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‎AlgoExpert/Remove Islands/RemoveIslands.swift

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Original file line numberDiff line numberDiff line change
@@ -0,0 +1,111 @@
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//
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// RemoveIslands.swift
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// Algorithm Solutions In Swift
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//
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// Created by Boudhayan Biswas on 04/07/22.
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//
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import Foundation
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// T: O(mn), S: (mn)
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func removeIslands(_ matrix: inout [[Int]]) -> [[Int]] {
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// go through the border and find 1.
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// if found 1, try to come inside and make every adjacent 1's to 2's
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//connected border 1's will be 2's
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// islands 1 will still exist as a
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// iterate through matrix
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// change 2 to 1 and 1 to 0
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for row in 0..<matrix.count {
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for col in 0..<matrix[0].count {
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if !isBorder(row, col, matrix) {
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continue
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}
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if row == 1 && col == 5 {
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print("")
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if matrix[row][col] == 0 || matrix[row][col] == 2 {
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continue
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}
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}
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changeBorderOnesToTwos(row, col, &matrix)
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}
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}
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for row in 0..<matrix.count {
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for col in 0..<matrix[0].count {
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if matrix[row][col] == 2 {
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matrix[row][col] = 1
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} else if matrix[row][col] == 1 {
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matrix[row][col] = 0
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} else {
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}
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}
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}
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return matrix
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}
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func isBorder(_ row: Int, _ col: Int, _ matrix: [[Int]]) -> Bool {
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return row == 0 || col == 0 || row == matrix.count - 1 || col == matrix[0].count - 1
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}
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func changeBorderOnesToTwos(_ row: Int, _ col: Int, _ matrix: inout [[Int]]) {
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var stack = [(Int, Int)]()
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stack.append((row, col))
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while !stack.isEmpty {
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let (r, c) = stack.removeLast()
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if matrix[r][c] == 0 || matrix[r][c] == 2 {
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continue
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}
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matrix[r][c] = 2
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stack += validNeighbours(r, c, matrix)
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}
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}
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func validNeighbours(_ row: Int, _ col: Int, _ matrix: [[Int]]) -> [(Int, Int)] {
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var neighbours = [(Int, Int)]()
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if row - 1 >= 0 {
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neighbours.append((row - 1, col))
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}
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if row + 1 <= matrix.count - 1 {
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neighbours.append((row + 1, col))
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}
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if col - 1 >= 0 {
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neighbours.append((row, col - 1))
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}
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if col + 1 <= matrix[0].count - 1 {
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neighbours.append((row, col + 1))
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}
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return neighbours
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}
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//var matrix = [
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// [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
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// [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1],
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// [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
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// [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
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// [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
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// [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
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// [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
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// [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
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// [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
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// [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
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// [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
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// [0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
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// [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
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// ]
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//print(removeIslands(&matrix))
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//
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///**
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// [
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// [2, 0, 0, 0, 0, 0],
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// [0, 1, 0, 2, 2, 2],
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// [0, 0, 1, 0, 2, 0],
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// [2, 2, 0, 0, 2, 0],
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// [2, 0, 1, 1, 0, 0],
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// [2, 0, 0, 0, 0, 2]
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// ]
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//
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//
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// */

‎Algorithm Solutions In Swift.xcodeproj/project.pbxproj

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Original file line numberDiff line numberDiff line change
@@ -15,6 +15,7 @@
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6A09C88827EDC29200BB9A38 /* ApartmentHunting+.swift in Sources */ = {isa = PBXBuildFile; fileRef = 6A09C88727EDC29200BB9A38 /* ApartmentHunting+.swift */; };
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6A09C88A27F03DF400BB9A38 /* Solution.swift in Sources */ = {isa = PBXBuildFile; fileRef = 6A09C88927F03DF400BB9A38 /* Solution.swift */; };
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@@ -266,6 +267,7 @@
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6A09C88727EDC29200BB9A38 /* ApartmentHunting+.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "ApartmentHunting+.swift"; sourceTree = "<group>"; };
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6A09C88927F03DF400BB9A38 /* Solution.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = Solution.swift; sourceTree = "<group>"; };
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6A2D1F062872CF600045048E /* RemoveIslands.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = RemoveIslands.swift; sourceTree = "<group>"; };
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@@ -515,6 +517,14 @@
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sourceTree = "<group>";
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};
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6A2D1F052872CF500045048E /* Remove Islands */ = {
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isa = PBXGroup;
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children = (
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6A2D1F062872CF600045048E /* RemoveIslands.swift */,
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);
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path = "Remove Islands";
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sourceTree = "<group>";
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};
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6A4364A927F4E5C800F09D92 /* Valid Parentheses */ = {
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isa = PBXGroup;
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children = (
@@ -1489,6 +1499,7 @@
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isa = PBXGroup;
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children = (
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6A2D1F052872CF500045048E /* Remove Islands */,
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6A67AE55286B132500DCD992 /* Number of Ways to Make Change */,
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6A67AE52286B125D00DCD992 /* Sort Stacks */,
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6A67AE4F2869CDAE00DCD992 /* Sunset Views */,
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6A2D1F072872CF600045048E /* RemoveIslands.swift in Sources */,
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6AF5791926A75668007B37CA /* AlmostSorted.swift in Sources */,
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6A88CF0C26C98D8300A3746B /* ReverseLinkedList.swift in Sources */,
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6AF5794A26AAC047007B37CA /* MergeSort.swift in Sources */,

‎Algorithm Solutions In Swift.xcodeproj/xcuserdata/boudhayan.xcuserdatad/xcschemes/xcschememanagement.plist

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Original file line numberDiff line numberDiff line change
@@ -7,12 +7,12 @@
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<key>Algorithm Solutions In Swift Tests.xcscheme_^#shared#^_</key>
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<dict>
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<key>orderHint</key>
10-
<integer>0</integer>
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<integer>1</integer>
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</dict>
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<key>Algorithm Solutions In Swift.xcscheme_^#shared#^_</key>
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<dict>
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<key>orderHint</key>
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<integer>1</integer>
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<integer>0</integer>
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</dict>
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</dict>
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</dict>

‎Pramp/Nth Root of Number/NthRoot.swift

+1-1
Original file line numberDiff line numberDiff line change
@@ -34,4 +34,4 @@ func accuracyTest(root: Double, x: Double, n: Double) -> Double {
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return pow(root, n) - x
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}
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//print(root(x: 7.0, n: 3.0))
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//;.lo;,iko ≤m    print(root(x: 7.0, n: 3.0))

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