Update 462-minimum-moves-to-equal-array-elements-II.js

Author: everthis

462-minimum-moves-to-equal-array-elements-II.js

@@ -14,3 +14,63 @@ const minMoves2 = function(nums) {
   }
   return res;
 };
+
+// another
+
+/**
+ * @param {number[]} nums
+ * @return {number}
+ */
+const minMoves2 = function (nums) {
+  const n = nums.length
+  const mid = Math.floor(n / 2)
+  const nth = nthElement(nums, mid, (a, b) => a - b)
+  let res = 0
+  for (let i = 0; i < n; i++) {
+    res += Math.abs(nums[i] - nth)
+  }
+
+  return res
+}
+
+function nthElement(arr, n, compareFn) {
+  if (n < 0 || n >= arr.length) {
+    throw new Error('Invalid index')
+  }
+
+  const partition = (arr, left, right, pivotIndex) => {
+    const pivotValue = arr[pivotIndex]
+    ;[arr[pivotIndex], arr[right]] = [arr[right], arr[pivotIndex]]
+    let storeIndex = left
+
+    for (let i = left; i < right; i++) {
+      if (compareFn(arr[i], pivotValue) < 0) {
+        ;[arr[i], arr[storeIndex]] = [arr[storeIndex], arr[i]]
+        storeIndex++
+      }
+    }
+
+    ;[arr[right], arr[storeIndex]] = [arr[storeIndex], arr[right]]
+    return storeIndex
+  }
+
+  const select = (arr, left, right, k) => {
+    if (left === right) {
+      return arr[left]
+    }
+
+    let pivotIndex = Math.floor(Math.random() * (right - left + 1)) + left
+    pivotIndex = partition(arr, left, right, pivotIndex)
+
+    if (k === pivotIndex) {
+      return arr[k]
+    } else if (k < pivotIndex) {
+      return select(arr, left, pivotIndex - 1, k)
+    } else {
+      return select(arr, pivotIndex + 1, right, k)
+    }
+  }
+
+  return select(arr, 0, arr.length - 1, n)
+}
+