Merge branch 'doocs:main' into main

Author: Nothing-avil

images/starcharts.svg

@@ -156,6 +156,28 @@ func canPartition(nums []int) bool {
 }
 ```
 
+#### Swift
+
+```swift
+class Solution {
+    func canPartition(_ nums: [Int]) -> Bool {
+        let s = nums.reduce(0, +)
+        if s % 2 != 0 { return false }
+        let target = s / 2
+        var dp = Array(repeating: false, count: target + 1)
+        dp[0] = true
+
+        for num in nums {
+            for j in stride(from: target, through: num, by: -1) {
+                dp[j] = dp[j] || dp[j - num]
+            }
+        }
+
+        return dp[target]
+    }
+}
+```
+
 <!-- tabs:end -->
 
 <!-- solution:end -->

lcof2/剑指 Offer II 101. 分割等和子串/README.md

@@ -0,0 +1,17 @@
+class Solution {
+    func canPartition(_ nums: [Int]) -> Bool {
+        let s = nums.reduce(0, +)
+        if s % 2 != 0 { return false }
+        let target = s / 2
+        var dp = Array(repeating: false, count: target + 1)
+        dp[0] = true
+        
+        for num in nums {
+            for j in stride(from: target, through: num, by: -1) {
+                dp[j] = dp[j] || dp[j - num]
+            }
+        }
+        
+        return dp[target]
+    }
+}

lcof2/剑指 Offer II 101. 分割等和子串/Solution.swift

@@ -163,6 +163,35 @@ func findTargetSumWays(nums []int, target int) int {
 }
 ```
 
+#### Swift
+
+```swift
+class Solution {
+    func findTargetSumWays(_ nums: [Int], _ target: Int) -> Int {
+        if target < -1000 || target > 1000 {
+            return 0
+        }
+
+        let n = nums.count
+        var dp = Array(repeating: Array(repeating: 0, count: 2001), count: n)
+
+        dp[0][nums[0] + 1000] += 1
+        dp[0][-nums[0] + 1000] += 1
+
+        for i in 1..<n {
+            for j in -1000...1000 {
+                if dp[i - 1][j + 1000] > 0 {
+                    dp[i][j + nums[i] + 1000] += dp[i - 1][j + 1000]
+                    dp[i][j - nums[i] + 1000] += dp[i - 1][j + 1000]
+                }
+            }
+        }
+
+        return dp[n - 1][target + 1000]
+    }
+}
+```
+
 <!-- tabs:end -->
 
 <!-- solution:end -->
@@ -241,6 +270,29 @@ func findTargetSumWays(nums []int, target int) int {
 }
 ```
 
+#### Swift
+
+```swift
+class Solution {
+    func findTargetSumWays(_ nums: [Int], _ target: Int) -> Int {
+        let s = nums.reduce(0, +)
+        if s - target < 0 || (s - target) % 2 != 0 {
+            return 0
+        }
+        let target = (s - target) / 2
+        var dp = [Int](repeating: 0, count: target + 1)
+        dp[0] = 1
+
+        for num in nums {
+            for j in stride(from: target, through: num, by: -1) {
+                dp[j] += dp[j - num]
+            }
+        }
+        return dp[target]
+    }
+}
+```
+
 <!-- tabs:end -->
 
 <!-- solution:end -->

lcof2/剑指 Offer II 102. 加减的目标值/README.md

@@ -0,0 +1,24 @@
+class Solution {
+    func findTargetSumWays(_ nums: [Int], _ target: Int) -> Int {
+        if target < -1000 || target > 1000 {
+            return 0
+        }
+        
+        let n = nums.count
+        var dp = Array(repeating: Array(repeating: 0, count: 2001), count: n)
+        
+        dp[0][nums[0] + 1000] += 1
+        dp[0][-nums[0] + 1000] += 1
+        
+        for i in 1..<n {
+            for j in -1000...1000 {
+                if dp[i - 1][j + 1000] > 0 {
+                    dp[i][j + nums[i] + 1000] += dp[i - 1][j + 1000]
+                    dp[i][j - nums[i] + 1000] += dp[i - 1][j + 1000]
+                }
+            }
+        }
+        
+        return dp[n - 1][target + 1000]
+    }
+}

lcof2/剑指 Offer II 102. 加减的目标值/Solution.swift

@@ -0,0 +1,18 @@
+class Solution {
+    func findTargetSumWays(_ nums: [Int], _ target: Int) -> Int {
+        let s = nums.reduce(0, +)
+        if s - target < 0 || (s - target) % 2 != 0 {
+            return 0
+        }
+        let target = (s - target) / 2
+        var dp = [Int](repeating: 0, count: target + 1)
+        dp[0] = 1
+        
+        for num in nums {
+            for j in stride(from: target, through: num, by: -1) {
+                dp[j] += dp[j - num]
+            }
+        }
+        return dp[target]
+    }
+}

lcof2/剑指 Offer II 102. 加减的目标值/Solution2.swift

@@ -169,6 +169,26 @@ var coinChange = function (coins, amount) {
 };
 ```
 
+#### Swift
+
+```swift
+class Solution {
+    func coinChange(_ coins: [Int], _ amount: Int) -> Int {
+        var dp = [Int](repeating: amount + 1, count: amount + 1)
+        dp[0] = 0
+
+        for coin in coins {
+            if coin > amount { continue }
+            for j in coin...amount {
+                dp[j] = min(dp[j], dp[j - coin] + 1)
+            }
+        }
+
+        return dp[amount] > amount ? -1 : dp[amount]
+    }
+}
+```
+
 <!-- tabs:end -->
 
 <!-- solution:end -->

lcof2/剑指 Offer II 103. 最少的硬币数目/README.md

@@ -0,0 +1,15 @@
+class Solution {
+    func coinChange(_ coins: [Int], _ amount: Int) -> Int {
+        var dp = [Int](repeating: amount + 1, count: amount + 1)
+        dp[0] = 0  
+
+        for coin in coins {
+            if coin > amount { continue }
+            for j in coin...amount {
+                dp[j] = min(dp[j], dp[j - coin] + 1)
+            }
+        }
+
+        return dp[amount] > amount ? -1 : dp[amount]
+    }
+}

lcof2/剑指 Offer II 103. 最少的硬币数目/Solution.swift

@@ -141,6 +141,27 @@ func combinationSum4(nums []int, target int) int {
 }
 ```
 
+#### Swift
+
+```swift
+class Solution {
+    func combinationSum4(_ nums: [Int], _ target: Int) -> Int {
+        var dp = [Int](repeating: 0, count: target + 1)
+        dp[0] = 1
+
+        for i in 1...target {
+            for num in nums {
+                if i >= num, dp[i] <= Int.max - dp[i - num] {
+                    dp[i] += dp[i - num]
+                }
+            }
+        }
+
+        return dp[target]
+    }
+}
+```
+
 <!-- tabs:end -->
 
 <!-- solution:end -->

lcof2/剑指 Offer II 104. 排列的数目/README.md

@@ -0,0 +1,16 @@
+class Solution {
+    func combinationSum4(_ nums: [Int], _ target: Int) -> Int {
+        var dp = [Int](repeating: 0, count: target + 1)
+        dp[0] = 1
+        
+        for i in 1...target {
+            for num in nums {
+                if i >= num, dp[i] <= Int.max - dp[i - num] {
+                    dp[i] += dp[i - num]
+                }
+            }
+        }
+
+        return dp[target]
+    }
+}