mod: avbv转换

lib/utils/id_utils.dart

@@ -0,0 +1,47 @@
+import 'dart:math';
+
+import 'package:flutter/material.dart';
+
+class IdUtils {
+  static const String TABLE =
+      'fZodR9XQDSUm21yCkr6zBqiveYah8bt4xsWpHnJE7jL5VG3guMTKNPAwcF';
+  static const List<int> S = [11, 10, 3, 8, 4, 6]; // 位置编码表
+  static const int XOR = 177451812; // 固定异或值
+  static const int ADD = 8728348608; // 固定加法值
+  static const List<String> r = [
+    'B',
+    'V',
+    '1',
+    '',
+    '',
+    '4',
+    '',
+    '1',
+    '',
+    '7',
+    '',
+    ''
+  ];
+
+  /// av转bv
+  static String av2bv(int av) {
+    int x_ = (av ^ XOR) + ADD;
+    List<String> newR = [];
+    newR.addAll(r);
+    for (int i = 0; i < S.length; i++) {
+      newR[S[i]] =
+          TABLE.characters.elementAt((x_ / pow(58, i).toInt() % 58).toInt());
+    }
+    return newR.join();
+  }
+
+  /// bv转bv
+  static int bv2av(String bv) {
+    int r = 0;
+    for (int i = 0; i < S.length; i++) {
+      r += (TABLE.indexOf(bv.characters.elementAt(S[i])).toInt()) *
+          pow(58, i).toInt();
+    }
+    return (r - ADD) ^ XOR;
+  }
+}