Merge pull request #695 from qxuewei/master

添加 1002. 查找常用字符 Swift版本

problems/0001.两数之和.md

@@ -206,6 +206,23 @@ function twoSum(array $nums, int $target): array
 }
 ```
 
+Swift：
+```swift
+func twoSum(_ nums: [Int], _ target: Int) -> [Int] {
+    var res = [Int]()
+    var dict = [Int : Int]()
+    for i in 0 ..< nums.count {
+        let other = target - nums[i]
+        if dict.keys.contains(other) {
+            res.append(i)
+            res.append(dict[other]!)
+            return res
+        }
+        dict[nums[i]] = i
+    }
+    return res
+}
+```
 
 -----------------------
 * 作者微信：[程序员Carl](https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw)

problems/0202.快乐数.md

@@ -191,7 +191,37 @@ var isHappy = function(n) {
 };
 ```
 
-
+Swift：
+```swift
+// number 每个位置上的数字的平方和
+func getSum(_ number: Int) -> Int {
+    var sum = 0
+    var num = number
+    while num > 0 {
+        let temp = num % 10
+        sum += (temp * temp)
+        num /= 10
+    }
+    return sum
+}
+func isHappy(_ n: Int) -> Bool {
+    var set = Set<Int>()
+    var num = n
+    while true {
+        let sum = self.getSum(num)
+        if sum == 1 {
+            return true
+        }
+        // 如果这个sum曾经出现过，说明已经陷入了无限循环了
+        if set.contains(sum) {
+            return false
+        } else {
+            set.insert(sum)
+        }
+        num = sum
+    }
+}
+```
 
 -----------------------
 * 作者微信：[程序员Carl](https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw)

problems/1002.查找常用字符.md

@@ -268,6 +268,47 @@ func min(a,b int)int{
     return a
 }
 ```
+
+Swift：
+```swift
+func commonChars(_ words: [String]) -> [String] {
+    var res = [String]()
+    if words.count < 1 {
+        return res
+    }
+    let aUnicodeScalarValue = "a".unicodeScalars.first!.value
+    let lettersMaxCount = 26
+    // 用于统计所有字符串每个字母出现的 最小 频率
+    var hash = Array(repeating: 0, count: lettersMaxCount)
+    // 统计第一个字符串每个字母出现的次数
+    for unicodeScalar in words.first!.unicodeScalars {
+        hash[Int(unicodeScalar.value - aUnicodeScalarValue)] += 1
+    }
+    // 统计除第一个字符串每个字母出现的次数
+    for idx in 1 ..< words.count {
+        var hashOtherStr = Array(repeating: 0, count: lettersMaxCount)
+        for unicodeScalar in words[idx].unicodeScalars {
+            hashOtherStr[Int(unicodeScalar.value - aUnicodeScalarValue)] += 1
+        }
+        // 更新hash,保证hash里统计的字母为出现的最小频率
+        for k in 0 ..< lettersMaxCount {
+            hash[k] = min(hash[k], hashOtherStr[k])
+        }
+    }
+    // 将hash统计的字符次数，转成输出形式
+    for i in 0 ..< lettersMaxCount {
+        while hash[i] != 0 { // 注意这里是while，多个重复的字符
+            let currentUnicodeScalarValue: UInt32 = UInt32(i) + aUnicodeScalarValue
+            let currentUnicodeScalar: UnicodeScalar = UnicodeScalar(currentUnicodeScalarValue)!
+            let outputStr = String(currentUnicodeScalar) // UnicodeScalar -> String
+            res.append(outputStr)
+            hash[i] -= 1
+        }
+    }
+    return res
+}
+```
+
 -----------------------
 * 作者微信：[程序员Carl](https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw)
 * B站视频：[代码随想录](https://space.bilibili.com/525438321)