add new easy problem 15.07

contest/src/main/java/com/github/contest/design/DesignLeetcode.kt

@@ -40,8 +40,7 @@ class ProductOfNumbers() {
 class WordDictionary() {
 
     data class TrieNode(
-        val children: MutableMap<Char, TrieNode> = mutableMapOf(),
-        var isEndOfWord: Boolean = false
+        val children: MutableMap<Char, TrieNode> = mutableMapOf(), var isEndOfWord: Boolean = false
     )
 
     private val root = TrieNode()
@@ -226,11 +225,7 @@ class CombinationIterator(characters: String, combinationLength: Int) {
     fun hasNext(): Boolean = store.isNotEmpty()
 
     private fun combine(
-        index: Int,
-        str: String,
-        subset: StringBuilder,
-        store: MutableList<String>,
-        limit: Int
+        index: Int, str: String, subset: StringBuilder, store: MutableList<String>, limit: Int
     ) {
 
         if (subset.length == limit) {
@@ -370,4 +365,42 @@ class StockSpanner() {
         return span
     }
 
+}
+
+/**
+ * 1865. Finding Pairs With a Certain Sum
+ */
+
+class FindSumPairs(private val nums1: IntArray, private val nums2: IntArray) {
+
+    private val second = mutableListOf<Long>()
+    private val freq = mutableMapOf<Long, Int>()
+
+    init {
+        for (elem in nums2) {
+            val e = elem.toLong()
+            second.add(e)
+            freq[e] = freq.getOrDefault(e, 0) + 1
+        }
+    }
+
+    fun add(index: Int, `val`: Int) {
+        val old = second[index]
+        second[index] = second[index] + `val`
+        val new = second[index]
+        freq[old] = freq.getOrDefault(old, 0) - 1
+        if (freq[old] == 0) freq.remove(old)
+        freq[new] = freq.getOrDefault(new, 0) + 1
+    }
+
+    fun count(tot: Int): Int {
+        var c = 0
+        for (elem in nums1) {
+            val target = tot - elem
+            if (freq.contains(target.toLong())) c += freq.getOrDefault(target.toLong(), 0)
+        }
+
+        return c
+    }
+
 }

contest/src/main/java/com/github/contest/strings/StringsLeetcode.kt

@@ -1,7 +1,5 @@
 package com.github.contest.strings
 
-import java.math.BigInteger
-
 /**
  * 848. Shifting Letters
  */
@@ -389,7 +387,6 @@ fun lengthOfLastWord(s: String): Int {
 }
 
 
-
 /**
  * 2138. Divide a String Into Groups of Size k
  */
@@ -438,4 +435,40 @@ private fun remainingFill(strs: Array<String>, pattern: Char, k: Int) {
     }
 }
 
+/**
+ * 3136. Valid Word
+ */
+
+fun isValid(word: String): Boolean {
+    if (word.length < 3) return false
+
+    var vowels = 0
+    var consonants = 0
+
+    for (char in word) {
+        if (isNotDigit(char) && isNotLetter(char)) return false
+        if (isLetter(char)) {
+            if (isVowel(char)) vowels++
+            else consonants++
+        }
+    }
+
+    return !(vowels == 0 || consonants == 0)
+}
+
+private fun isNotDigit(char: Char) = when {
+    char in '0'..'9' -> false
+    else -> true
+}
+
+private fun isNotLetter(char: Char) = when {
+    char in 'a'..'z' || char in 'A'..'Z' -> false
+    else -> true
+}
+
+private fun isVowel(char: Char) = when {
+    char in "aeiou" || char in "AEIOU" -> true
+    else -> false
+}
+