From 00f6a80ab185fb1f532af1e9261059dcf49a004c Mon Sep 17 00:00:00 2001
From: yigencong <yigencong@yahoo.com>
Date: Wed, 28 Feb 2024 13:04:04 +0800
Subject: [PATCH] =?UTF-8?q?feat:=20=E5=BF=AB=E9=80=9F=E6=8E=92=E5=BA=8F?=
 =?UTF-8?q?=E7=9A=84=E5=BA=94=E7=94=A8=EF=BC=8Ctopk=E9=97=AE=E9=A2=98?=
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---
 sort/practice.mjs | 53 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 53 insertions(+)
 create mode 100644 sort/practice.mjs

diff --git a/sort/practice.mjs b/sort/practice.mjs
new file mode 100644
index 0000000..0df5f47
--- /dev/null
+++ b/sort/practice.mjs
@@ -0,0 +1,53 @@
+/**
+ *
+ * @param {number[]} arr - 需要操作的数组
+ * @param {number} k  - 需要找的多少个数
+ */
+function topK(arr, k) {
+  if (k > arr.length) {
+    throw new Error(`数组的长度必须大于${k}`);
+  }
+  let low = 0;
+  let high = arr.length - 1;
+  let pivot = partition(arr, low, high);
+  while (pivot !== k - 1) { // 如果k等于pivot-1说明就找到了
+    if (pivot > k - 1) {
+      high = pivot - 1;
+      pivot = partition(arr, low, high);
+    }
+    if (pivot < k - 1) {
+      low = pivot + 1;
+      pivot = partition(arr, low, high);
+    }
+  }
+  return arr.slice(0, k);
+}
+
+/**
+ * @description 使用经典的挖坑法
+ * @param {number[]} 要分解的数组
+ * @param {*} low 开始下标
+ * @param {*} high 结束下标
+ */
+function partition(arr, low, high) {
+  const pivot = arr[high]; // 默认以最后一个数为枢纽
+  while (low < high) {
+    // low找比pivot大的数
+    while (low < high && arr[low] < pivot) {
+      low++;
+    }
+    arr[high] = arr[low];
+    while (low < high && arr[high] > pivot) {
+      high--;
+    }
+    arr[low] = arr[high];
+  }
+  arr[low] = pivot;
+  return low;
+}
+
+// test
+
+const arr = [11, 9, 6, 17, 0, 1, 2, 18, 3, 4, 8, 5];
+const ret = topK(arr, 100);
+console.log(ret);