feat: add solutions to lcci problems: No.01.04,01.05 (#2577)

doocs · Apr 13, 2024 · 696d844 · 696d844
1 parent 1345b3c
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diff --git a/lcci/01.04.Palindrome Permutation/README.md b/lcci/01.04.Palindrome Permutation/README.md
@@ -120,6 +120,24 @@ impl Solution {
 }
 ```
 
+```swift
+class Solution {
+    func canPermutePalindrome(_ s: String) -> Bool {
+        var cnt = [Character: Int]()
+        for char in s {
+            cnt[char, default: 0] += 1
+        }
+
+        var sum = 0
+        for count in cnt.values {
+            sum += count % 2
+        }
+
+        return sum < 2
+    }
+}
+```
+
 <!-- tabs:end -->
 
 ### 方法二：哈希表的另一种实现

diff --git a/lcci/01.04.Palindrome Permutation/README_EN.md b/lcci/01.04.Palindrome Permutation/README_EN.md
@@ -117,6 +117,24 @@ impl Solution {
 }
 ```
 
+```swift
+class Solution {
+    func canPermutePalindrome(_ s: String) -> Bool {
+        var cnt = [Character: Int]()
+        for char in s {
+            cnt[char, default: 0] += 1
+        }
+
+        var sum = 0
+        for count in cnt.values {
+            sum += count % 2
+        }
+
+        return sum < 2
+    }
+}
+```
+
 <!-- tabs:end -->
 
 ### Solution 2: Another Implementation of Hash Table

diff --git a/lcci/01.04.Palindrome Permutation/Solution.swift b/lcci/01.04.Palindrome Permutation/Solution.swift
@@ -0,0 +1,15 @@
+class Solution {
+    func canPermutePalindrome(_ s: String) -> Bool {
+        var cnt = [Character: Int]()
+        for char in s {
+            cnt[char, default: 0] += 1
+        }
+
+        var sum = 0
+        for count in cnt.values {
+            sum += count % 2
+        }
+
+        return sum < 2
+    }
+}
diff --git a/lcci/01.05.One Away/README.md b/lcci/01.05.One Away/README.md
@@ -223,6 +223,48 @@ impl Solution {
 }
 ```
 
+```swift
+class Solution {
+    func oneEditAway(_ first: String, _ second: String) -> Bool {
+        let m = first.count, n = second.count
+        if m < n {
+            return oneEditAway(second, first)
+        }
+        if m - n > 1 {
+            return false
+        }
+
+        var cnt = 0
+        var firstIndex = first.startIndex
+        var secondIndex = second.startIndex
+
+        if m == n {
+            while secondIndex != second.endIndex {
+                if first[firstIndex] != second[secondIndex] {
+                    cnt += 1
+                    if cnt > 1 {
+                        return false
+                    }
+                }
+                firstIndex = first.index(after: firstIndex)
+                secondIndex = second.index(after: secondIndex)
+            }
+            return true
+        } else {
+            while firstIndex != first.endIndex {
+                if secondIndex == second.endIndex || (secondIndex != second.endIndex && first[firstIndex] != second[secondIndex]) {
+                    cnt += 1
+                } else {
+                    secondIndex = second.index(after: secondIndex)
+                }
+                firstIndex = first.index(after: firstIndex)
+            }
+        }
+        return cnt < 2
+    }
+}
+```
+
 <!-- tabs:end -->
 
 <!-- end -->
diff --git a/lcci/01.05.One Away/README_EN.md b/lcci/01.05.One Away/README_EN.md
@@ -231,6 +231,48 @@ impl Solution {
 }
 ```
 
+```swift
+class Solution {
+    func oneEditAway(_ first: String, _ second: String) -> Bool {
+        let m = first.count, n = second.count
+        if m < n {
+            return oneEditAway(second, first)
+        }
+        if m - n > 1 {
+            return false
+        }
+
+        var cnt = 0
+        var firstIndex = first.startIndex
+        var secondIndex = second.startIndex
+
+        if m == n {
+            while secondIndex != second.endIndex {
+                if first[firstIndex] != second[secondIndex] {
+                    cnt += 1
+                    if cnt > 1 {
+                        return false
+                    }
+                }
+                firstIndex = first.index(after: firstIndex)
+                secondIndex = second.index(after: secondIndex)
+            }
+            return true
+        } else {
+            while firstIndex != first.endIndex {
+                if secondIndex == second.endIndex || (secondIndex != second.endIndex && first[firstIndex] != second[secondIndex]) {
+                    cnt += 1
+                } else {
+                    secondIndex = second.index(after: secondIndex)
+                }
+                firstIndex = first.index(after: firstIndex)
+            }
+        }
+        return cnt < 2
+    }
+}
+```
+
 <!-- tabs:end -->
 
 <!-- end -->
diff --git a/lcci/01.05.One Away/Solution.swift b/lcci/01.05.One Away/Solution.swift
@@ -0,0 +1,39 @@
+class Solution {
+    func oneEditAway(_ first: String, _ second: String) -> Bool {
+        let m = first.count, n = second.count
+        if m < n {
+            return oneEditAway(second, first)
+        }
+        if m - n > 1 {
+            return false
+        }
+
+        var cnt = 0
+        var firstIndex = first.startIndex
+        var secondIndex = second.startIndex
+
+        if m == n {
+            while secondIndex != second.endIndex {
+                if first[firstIndex] != second[secondIndex] {
+                    cnt += 1
+                    if cnt > 1 {
+                        return false
+                    }
+                }
+                firstIndex = first.index(after: firstIndex)
+                secondIndex = second.index(after: secondIndex)
+            }
+            return true
+        } else {
+            while firstIndex != first.endIndex {
+                if secondIndex == second.endIndex || (secondIndex != second.endIndex && first[firstIndex] != second[secondIndex]) {
+                    cnt += 1
+                } else {
+                    secondIndex = second.index(after: secondIndex)
+                }
+                firstIndex = first.index(after: firstIndex)
+            }
+        }
+        return cnt < 2
+    }
+}