From 047ff76e3a51c2b57ca4d65c047e9080eb17c2f1 Mon Sep 17 00:00:00 2001
From: zhl <zhl010101@gmail.com>
Date: Fri, 8 Jan 2021 17:39:23 +0800
Subject: [PATCH] =?UTF-8?q?=E6=B7=BB=E5=8A=A03=E4=B8=AA=E6=95=B0=E7=BB=84?=
 =?UTF-8?q?=E6=B1=82=E5=B9=B6=E9=9B=86,=E4=BA=A4=E9=9B=86=E5=92=8C?=
 =?UTF-8?q?=E5=B7=AE=E9=9B=86=E7=9A=84=E6=96=B9=E6=B3=95?=
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---
 src/common/Extend.ts | 43 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 43 insertions(+)

diff --git a/src/common/Extend.ts b/src/common/Extend.ts
index 6173789..9d82a79 100644
--- a/src/common/Extend.ts
+++ b/src/common/Extend.ts
@@ -563,6 +563,23 @@ interface Array<T> {
      * @param n n > 0 右移, n<0 左移
      */
     moveElement?<T>(n: number): T[];
+
+    /**
+     * 两个数组并集
+     * @param arr
+     */
+    union?<T>(arr: T[]): T[];
+
+    /**
+     * 两个数组交集
+     * @param arr
+     */
+    intersect?<T>(arr: T[]): T[];
+    /**
+     * 相对于arr的差集
+     * @param arr
+     */
+    difference?<T>(arr: T[]): T[];
 }
 
 Object.defineProperties(Array.prototype, {
@@ -815,6 +832,32 @@ Object.defineProperties(Array.prototype, {
             return this.slice(-n).concat(this.slice(0, -n));
         },
         writable: true
+    },
+
+    union: {
+        value: function<T> (this: T[], b: any[]): T[] {
+            let a = this.concat(b);
+            return [...new Set(a)];
+        },
+        writable: true
+    },
+
+    intersect: {
+        value: function<T> (this: T[], b: any[]): T[] {
+            let set0 = new Set(b);
+            let set1 = new Set(this.filter (x => set0.has(x)));
+            return [...set1];
+        },
+        writable: true
+    },
+
+    difference: {
+        value: function<T> (this: T[], b: any[]): T[] {
+            let set0 = new Set(b);
+            let set1 = new Set(this.filter(x => !set0.has(x)));
+            return [...set1];
+        },
+        writable: true
     }
 
 });