Merge pull request #177

add new problem and repeat old 17.04

Author: Ashwagandha-coder

contest/src/main/java/com/github/contest/hashTable/HashTableLeetcode.kt

@@ -365,4 +365,50 @@ fun countGood(nums: IntArray, k: Int): Long {
 private fun IntArray.hasSingle() = when {
     this.size == 1 -> true
     else -> false
+}
+
+
+/**
+ * 169. Majority Element
+ */
+
+fun majorityElement(nums: IntArray): Int {
+    var majority = 0
+    var res = 0
+    val target = nums.size / 2
+
+    nums.forEach {
+        if (majority == 0) res = it
+        majority += when {
+            it == res -> 1
+            else -> -1
+        }
+    }
+
+    return res
+}
+
+/**
+ * 2176. Count Equal and Divisible Pairs in an Array
+ */
+
+fun countPairs(nums: IntArray, k: Int): Int {
+    if (nums.size < 2) return 0
+
+    val store = mutableMapOf<Int, MutableList<Int>>()
+    var count = 0
+
+    for (i in nums.indices) {
+        val num = nums[i]
+        if (store.contains(num)) {
+            val indexed = store.getOrDefault(num, mutableListOf())
+            for (index in indexed) {
+                if ((index * i) % k == 0) count++
+            }
+            indexed.add(i)
+            store[num] = indexed
+        } else store[num] = mutableListOf(i)
+    }
+
+    return count
 }