Added tasks 341-400.

Author: javadev

README.md

@@ -72,6 +72,7 @@ import com_github_leetcode.TreeNode
  */
 class Solution {
     private var sum = 0
+
     fun sumNumbers(root: TreeNode): Int {
         recurseSum(root, 0)
         return sum

src/main/kotlin/g0101_0200/s0129_sum_root_to_leaf_numbers/readme.md

@@ -37,8 +37,8 @@ A -> 1 B -> 2 C -> 3 ... Z -> 26 AA -> 27 AB -> 28 ...
 
 ```kotlin
 class Solution {
-    fun convertToTitle(n: Int): String {
-        var num = n
+    fun convertToTitle(columnNumber: Int): String {
+        var num = columnNumber
         val sb = StringBuilder()
         while (num != 0) {
             var remainder = num % 26

src/main/kotlin/g0101_0200/s0168_excel_sheet_column_title/readme.md

@@ -0,0 +1,109 @@
+[![](https://img.shields.io/github/stars/javadev/LeetCode-in-Kotlin?label=Stars&style=flat-square)](https://github.com/javadev/LeetCode-in-Kotlin)
+[![](https://img.shields.io/github/forks/javadev/LeetCode-in-Kotlin?label=Fork%20me%20on%20GitHub%20&style=flat-square)](https://github.com/javadev/LeetCode-in-Kotlin/fork)
+
+## 341\. Flatten Nested List Iterator
+
+Medium
+
+You are given a nested list of integers `nestedList`. Each element is either an integer or a list whose elements may also be integers or other lists. Implement an iterator to flatten it.
+
+Implement the `NestedIterator` class:
+
+*   `NestedIterator(List<NestedInteger> nestedList)` Initializes the iterator with the nested list `nestedList`.
+*   `int next()` Returns the next integer in the nested list.
+*   `boolean hasNext()` Returns `true` if there are still some integers in the nested list and `false` otherwise.
+
+Your code will be tested with the following pseudocode:
+
+    initialize iterator with nestedList
+    res = []
+    while iterator.hasNext()
+        append iterator.next() to the end of res
+    return res 
+
+If `res` matches the expected flattened list, then your code will be judged as correct.
+
+**Example 1:**
+
+**Input:** nestedList = \[\[1,1],2,[1,1]]
+
+**Output:** [1,1,2,1,1]
+
+**Explanation:** By calling next repeatedly until hasNext returns false, the order of elements returned by next should be: [1,1,2,1,1]. 
+
+**Example 2:**
+
+**Input:** nestedList = [1,[4,[6]]]
+
+**Output:** [1,4,6]
+
+**Explanation:** By calling next repeatedly until hasNext returns false, the order of elements returned by next should be: [1,4,6]. 
+
+**Constraints:**
+
+*   `1 <= nestedList.length <= 500`
+*   The values of the integers in the nested list is in the range <code>[-10<sup>6</sup>, 10<sup>6</sup>]</code>.
+
+## Solution
+
+```kotlin
+import com_github_leetcode.NestedInteger
+
+/*
+ * // This is the interface that allows for creating nested lists.
+ * // You should not implement it, or speculate about its implementation
+ * class NestedInteger {
+ *     // Constructor initializes an empty nested list.
+ *     constructor()
+ *
+ *     // Constructor initializes a single integer.
+ *     constructor(value: Int)
+ *
+ *     // @return true if this NestedInteger holds a single integer, rather than a nested list.
+ *     fun isInteger(): Boolean
+ *
+ *     // @return the single integer that this NestedInteger holds, if it holds a single integer
+ *     // Return null if this NestedInteger holds a nested list
+ *     fun getInteger(): Int?
+ *
+ *     // Set this NestedInteger to hold a single integer.
+ *     fun setInteger(value: Int): Unit
+ *
+ *     // Set this NestedInteger to hold a nested list and adds a nested integer to it.
+ *     fun add(ni: NestedInteger): Unit
+ *
+ *     // @return the nested list that this NestedInteger holds, if it holds a nested list
+ *     // Return null if this NestedInteger holds a single integer
+ *     fun getList(): List<NestedInteger>?
+ * }
+ */
+class NestedIterator(nestedList: List<NestedInteger>) {
+    private var flattenList = mutableListOf<Int>()
+    private var index = 0
+
+    init {
+        flatten(nestedList, flattenList)
+    }
+
+    private fun flatten(nestedList: List<NestedInteger>, flattenList: MutableList<Int>) {
+        nestedList.forEach { nestedInteger ->
+            if (nestedInteger.isInteger()) {
+                flattenList.add(nestedInteger.getInteger()!!)
+            } else {
+                flatten(nestedInteger.getList()!!, flattenList)
+            }
+        }
+    }
+
+    fun next(): Int = flattenList[index++]
+
+    fun hasNext(): Boolean = index < flattenList.size
+}
+
+/*
+ * Your NestedIterator object will be instantiated and called as such:
+ * var obj = NestedIterator(nestedList)
+ * var param_1 = obj.next()
+ * var param_2 = obj.hasNext()
+ */
+```

src/main/kotlin/g0301_0400/s0341_flatten_nested_list_iterator/readme.md

@@ -0,0 +1,71 @@
+[![](https://img.shields.io/github/stars/javadev/LeetCode-in-Kotlin?label=Stars&style=flat-square)](https://github.com/javadev/LeetCode-in-Kotlin)
+[![](https://img.shields.io/github/forks/javadev/LeetCode-in-Kotlin?label=Fork%20me%20on%20GitHub%20&style=flat-square)](https://github.com/javadev/LeetCode-in-Kotlin/fork)
+
+## 371\. Sum of Two Integers
+
+Medium
+
+Given two integers `a` and `b`, return _the sum of the two integers without using the operators_ `+` _and_ `-`.
+
+**Example 1:**
+
+**Input:** a = 1, b = 2
+
+**Output:** 3
+
+**Example 2:**
+
+**Input:** a = 2, b = 3
+
+**Output:** 5
+
+**Constraints:**
+
+*   `-1000 <= a, b <= 1000`
+
+## Solution
+
+```kotlin
+@Suppress("NAME_SHADOWING")
+class Solution {
+    fun getSum(a: Int, b: Int): Int {
+        var a = a
+        var b = b
+        var ans = 0
+        var memo = 0
+        var exp = 0
+        var count = 0
+        while (count < 32) {
+            val val1 = a and 1
+            val val2 = b and 1
+            var `val` = sum(val1, val2, memo)
+            memo = `val` shr 1
+            `val` = `val` and 1
+            a = a shr 1
+            b = b shr 1
+            ans = ans or (`val` shl exp)
+            exp = plusOne(exp)
+            count = plusOne(count)
+        }
+        return ans
+    }
+
+    private fun sum(val1: Int, val2: Int, val3: Int): Int {
+        var count = 0
+        if (val1 == 1) {
+            count = plusOne(count)
+        }
+        if (val2 == 1) {
+            count = plusOne(count)
+        }
+        if (val3 == 1) {
+            count = plusOne(count)
+        }
+        return count
+    }
+
+    private fun plusOne(`val`: Int): Int {
+        return -`val`.inv()
+    }
+}
+```

src/main/kotlin/g0301_0400/s0371_sum_of_two_integers/readme.md

@@ -0,0 +1,112 @@
+[![](https://img.shields.io/github/stars/javadev/LeetCode-in-Kotlin?label=Stars&style=flat-square)](https://github.com/javadev/LeetCode-in-Kotlin)
+[![](https://img.shields.io/github/forks/javadev/LeetCode-in-Kotlin?label=Fork%20me%20on%20GitHub%20&style=flat-square)](https://github.com/javadev/LeetCode-in-Kotlin/fork)
+
+## 372\. Super Pow
+
+Medium
+
+Your task is to calculate <code>a<sup>b</sup></code> mod `1337` where `a` is a positive integer and `b` is an extremely large positive integer given in the form of an array.
+
+**Example 1:**
+
+**Input:** a = 2, b = [3]
+
+**Output:** 8
+
+**Example 2:**
+
+**Input:** a = 2, b = [1,0]
+
+**Output:** 1024
+
+**Example 3:**
+
+**Input:** a = 1, b = [4,3,3,8,5,2]
+
+**Output:** 1
+
+**Constraints:**
+
+*   <code>1 <= a <= 2<sup>31</sup> - 1</code>
+*   `1 <= b.length <= 2000`
+*   `0 <= b[i] <= 9`
+*   `b` does not contain leading zeros.
+
+## Solution
+
+```kotlin
+@Suppress("NAME_SHADOWING")
+class Solution {
+    fun superPow(a: Int, b: IntArray): Int {
+        val phi = phi(MOD)
+        val arrMod = arrMod(b, phi)
+        return if (isGreaterOrEqual(b, phi)) {
+            // Cycle has started
+            // cycle starts at phi with length phi
+            exp(a % MOD, phi + arrMod)
+        } else exp(a % MOD, arrMod)
+    }
+
+    private fun phi(n: Int): Int {
+        var n = n
+        var result = n.toDouble()
+        var p = 2
+        while (p * p <= n) {
+            if (n % p > 0) {
+                p++
+                continue
+            }
+            while (n % p == 0) {
+                n /= p
+            }
+            result *= 1.0 - 1.0 / p
+            p++
+        }
+        if (n > 1) {
+            // if starting n was also prime (so it was greater than sqrt(n))
+            result *= 1.0 - 1.0 / n
+        }
+        return result.toInt()
+    }
+
+    // Returns true if number in array is greater than integer named phi
+    private fun isGreaterOrEqual(b: IntArray, phi: Int): Boolean {
+        var cur = 0
+        for (j in b) {
+            cur = cur * 10 + j
+            if (cur >= phi) {
+                return true
+            }
+        }
+        return false
+    }
+
+    // Returns number in array mod phi
+    private fun arrMod(b: IntArray, phi: Int): Int {
+        var res = 0
+        for (j in b) {
+            res = (res * 10 + j) % phi
+        }
+        return res
+    }
+
+    // Binary exponentiation
+    private fun exp(a: Int, b: Int): Int {
+        var a = a
+        var b = b
+        var y = 1
+        while (b > 0) {
+            if (b % 2 == 1) {
+                y = y * a % MOD
+            }
+            a = a * a % MOD
+            b /= 2
+        }
+        return y
+    }
+
+    companion object {
+        private const val MOD = 1337
+    }
+}
+```