Merge remote-tracking branch 'origin/master'

Author: Mukyu

README.md

@@ -36,9 +36,9 @@
 | [021][021-question] | [Merge Two Sorted Lists][021-tips]                           | [✅][021-java] |              | [✅][021-kotlin] |
 | [026][026-question] | [Remove Duplicates from Sorted Array][026-tips]              | [✅][026-java] |              | [✅][026-kotlin] |
 | [027][027-question] | [Remove Element][027-tips]                                   | [✅][027-java] |              | [✅][027-kotlin] |
-| [028][028-question] | [Implement strStr()][028-tips]                               | [✅][028-java] |              |                  |
-| [035][035-question] | [Search Insert Position][035-tips]                           | [✅][035-java] |              |                  |
-| [038][038-question] | [Count and Say][038-tips]                                    | [✅][038-java] |              |                  |
+| [028][028-question] | [Implement strStr()][028-tips]                               | [✅][028-java] |              | [✅][028-kotlin] |
+| [035][035-question] | [Search Insert Position][035-tips]                           | [✅][035-java] |              | [✅][035-kotlin] |
+| [038][038-question] | [Count and Say][038-tips]                                    | [✅][038-java] |              | [✅][038-kotlin] |
 | [053][053-question] | [Maximum Subarray][053-tips]                                 | [✅][053-java] |              |                  |
 | [058][058-question] | [Length of Last Word][058-tips]                              | [✅][058-java] |              |                  |
 | [066][066-question] | [Plus One][066-tips]                                         | [✅][066-java] |              |                  |
@@ -471,4 +471,7 @@
 [021-kotlin]: ./src/_021/kotlin/Solution.kt
 [026-kotlin]: ./src/_026/kotlin/Solution.kt
 [027-kotlin]: ./src/_027/kotlin/Solution.kt
+[028-kotlin]: ./src/_028/kotlin/Solution.kt
+[035-kotlin]: ./src/_035/kotlin/Solution.kt
+[038-kotlin]: ./src/_038/kotlin/Solution.kt
 [771-kotlin]: ./src/_771/kotlin/Solution.kt

src/_028/kotlin/Solution.kt

@@ -0,0 +1,50 @@
+package _028.kotlin
+
+/**
+ * @author relish
+ * @since 2018/04/15
+ */
+class Solution {
+    fun strStr(haystack: String, needle: String): Int {
+        
+        if (haystack.isEmpty()) {
+            return if (needle.isEmpty()) haystack.length else -1
+        }
+        if (needle.isEmpty()) {
+            return 0
+        }
+
+        val first = needle[0]
+        val max = 0 + (haystack.length - needle.length)
+
+        var i = 0 + 0
+        while (i <= max) {
+            /* Look for first character. */
+            if (haystack[i] != first) {
+                while (++i <= max && haystack[i] != first);
+            }
+
+            /* Found first character, now look at the rest of v2 */
+            if (i <= max) {
+                var j = i + 1
+                val end = j + needle.length - 1
+                var k = 0 + 1
+                while (j < end && haystack[j] == needle[k]) {
+                    j++
+                    k++
+                }
+
+                if (j == end) {
+                    /* Found whole string. */
+                    return i - 0
+                }
+            }
+            i++
+        }
+        return -1
+    }
+}
+
+fun main(args: Array<String>) {
+    println(Solution().strStr("hello",""))
+}

src/_035/kotlin/Solution.kt

@@ -0,0 +1,25 @@
+package _035.kotlin
+
+/**
+ * @author relish
+ * @since 2018/04/15
+ */
+class Solution {
+    fun searchInsert(nums: IntArray, target: Int): Int {
+        var left = 0
+        var right = nums.size - 1
+        while (left <= right) {
+            val mid = (left + right) / 2
+            when {
+                nums[mid] == target -> return mid
+                nums[mid] < target -> left = mid + 1
+                else -> right = mid - 1
+            }
+        }
+        return left
+    }
+}
+
+fun main(args: Array<String>) {
+    println(Solution().searchInsert(intArrayOf(1,3,5,6), 5))
+}

src/_038/kotlin/Solution.kt

@@ -0,0 +1,38 @@
+package _038.kotlin
+
+/**
+ * @author relish
+ * @since 2018/04/16
+ */
+class Solution {
+    fun countAndSay(n: Int): String {
+        var say = "1"
+        for (count in 1 until n) {
+            say = say(say)
+        }
+        return say
+    }
+
+    private fun say(say: String): String {
+        val newSay = StringBuilder()
+        var prev = say[0]
+        var tCount = 0
+        for (i in say.indices) {
+            if (say[i] == prev) {
+                tCount++
+                continue
+            }
+            newSay.append(tCount).append(prev)
+            prev = say[i]
+            tCount = 1
+        }
+        newSay.append(tCount).append(prev)
+        return newSay.toString()
+    }
+}
+
+fun main(args: Array<String>) {
+    for (i in 1 until 10) {
+        println(Solution().countAndSay(i))
+    }
+}

tips/028/README.md

@@ -26,7 +26,7 @@ Tags:** Two Pointers, String
 ## 思路
 
 题意是从主串中找到子串的索引，如果找不到则返回-1，当子串长度大于主串，直接返回-1，然后我们只需要遍历比较即可。
-
+Java:
 ```java
 class Solution {
     public int strStr(String haystack, String needle) {
@@ -42,6 +42,49 @@ class Solution {
     }
 }
 ```
+kotlin(200ms/87.50%):
+```kotlin
+class Solution {
+    fun strStr(haystack: String, needle: String): Int {
+        
+        if (haystack.isEmpty()) {
+            return if (needle.isEmpty()) haystack.length else -1
+        }
+        if (needle.isEmpty()) {
+            return 0
+        }
+
+        val first = needle[0]
+        val max = 0 + (haystack.length - needle.length)
+
+        var i = 0 + 0
+        while (i <= max) {
+            /* Look for first character. */
+            if (haystack[i] != first) {
+                while (++i <= max && haystack[i] != first);
+            }
+
+            /* Found first character, now look at the rest of v2 */
+            if (i <= max) {
+                var j = i + 1
+                val end = j + needle.length - 1
+                var k = 0 + 1
+                while (j < end && haystack[j] == needle[k]) {
+                    j++
+                    k++
+                }
+
+                if (j == end) {
+                    /* Found whole string. */
+                    return i - 0
+                }
+            }
+            i++
+        }
+        return -1
+    }
+}
+```
 
 
 ## 结语

tips/035/README.md

@@ -41,6 +41,7 @@ Output: 0
 
 题意是让你从一个没有重复元素的已排序数组中找到插入位置的索引。因为数组已排序，所以我们可以想到二分查找法，因为查找到的条件是找到第一个等于或者大于 `target` 的元素的位置，所以二分法略作变动即可。
 
+Java:
 ```java
 class Solution {
     public int searchInsert(int[] nums, int target) {
@@ -55,6 +56,25 @@ class Solution {
 }
 ```
 
+kotlin(216ms/90.00%):
+```kotlin
+class Solution {
+    fun searchInsert(nums: IntArray, target: Int): Int {
+        var left = 0
+        var right = nums.size - 1
+        while (left <= right) {
+            val mid = (left + right) / 2
+            when {
+                nums[mid] == target -> return mid
+                nums[mid] < target -> left = mid + 1
+                else -> right = mid - 1
+            }
+        }
+        return left
+    }
+}
+```
+
 
 ## 结语
 

tips/038/README.md

@@ -43,6 +43,7 @@ Output: "1211"
 
 题意是数和说，根据如下序列 `1, 11, 21, 1211, 111221, ...`，求第 n 个数，规则很简单,就是数和说，数就是数这个数数字有几个，说就是说这个数，所以 `1` 就是 1 个 1：`11`,`11` 就是有 2 个 1：`21`，`21` 就是 1 个 2、1 个 1：`1211`，可想而知后面就是 `111221`，思路的话就是按这个逻辑模拟出来即可。
 
+Java:
 ```java
 class Solution {
     public String countAndSay(int n) {
@@ -67,6 +68,37 @@ class Solution {
 }
 ```
 
+kotlin(172ms/100.00%):
+```kotlin
+class Solution {
+    fun countAndSay(n: Int): String {
+        var say = "1"
+        for (count in 1 until n) {
+            say = say(say)
+        }
+        return say
+    }
+
+    private fun say(say: String): String {
+        val newSay = StringBuilder()
+        var prev = say[0]
+        var tCount = 0
+        for (i in say.indices) {
+            if (say[i] == prev) {
+                tCount++
+                continue
+            }
+            newSay.append(tCount).append(prev)
+            prev = say[i]
+            tCount = 1
+        }
+        newSay.append(tCount).append(prev)
+        return newSay.toString()
+    }
+}
+
+```
+
 
 ## 结语