GB2312简体中文编码中16-55区为一级汉字，按拼音排序，共3755个。据此可以利用表查询的方法得到汉字的拼音。
具体做法是用汉字的GB2312编码作为索引，利用二分法查找。
下面是GB2312编码中一级汉字的拼音查找表：
var LUT = [
'a', 0xb0a1, 'ai', 0xb0a3, 'an', 0xb0b0, 'ang', 0xb0b9, 'ao', 0xb0bc,
'ba', 0xb0c5, 'bai', 0xb0d7, 'ban', 0xb0df, 'bang', 0xb0ee, 'bao', 0xb0fa,
'bei', 0xb1ad, 'ben', 0xb1bc, 'beng', 0xb1c0, 'bi', 0xb1c6, 'bian', 0xb1de,
'biao', 0xb1ea, 'bie', 0xb1ee, 'bin', 0xb1f2, 'bing', 0xb1f8, 'bo', 0xb2a3,
'bu', 0xb2b8, 'ca', 0xb2c1, 'cai', 0xb2c2, 'can', 0xb2cd, 'cang', 0xb2d4,
'cao', 0xb2d9, 'ce', 0xb2de, 'ceng', 0xb2e3, 'cha', 0xb2e5, 'chai', 0xb2f0,
'chan', 0xb2f3, 'chang', 0xb2fd, 'chao', 0xb3ac, 'che', 0xb3b5, 'chen', 0xb3bb,
'cheng', 0xb3c5, 'chi', 0xb3d4, 'chong', 0xb3e4, 'chou', 0xb3e9, 'chu', 0xb3f5,
'chuai', 0xb4a7, 'chuan', 0xb4a8,'chuang', 0xb4af, 'chui', 0xb4b5, 'chun', 0xb4ba,
'chuo', 0xb4c1, 'ci', 0xb4c3, 'cong', 0xb4cf, 'cou', 0xb4d5, 'cu', 0xb4d6,
'cuan', 0xb4da, 'cui', 0xb4dd, 'cun', 0xb4e5, 'cuo', 0xb4e8, 'da', 0xb4ee,
'dai', 0xb4f4, 'dan', 0xb5a2, 'dang', 0xb5b1, 'dao', 0xb5b6, 'de', 0xb5c2,
'deng', 0xb5c5, 'di', 0xb5cc, 'dian', 0xb5df, 'diao', 0xb5ef, 'die', 0xb5f8,
'ding', 0xb6a1, 'diu', 0xb6aa, 'dong', 0xb6ab, 'dou', 0xb6b5, 'du', 0xb6bc,
'duan', 0xb6cb, 'dui', 0xb6d1, 'dun', 0xb6d5, 'duo', 0xb6de, 'e', 0xb6ea,
'en', 0xb6f7, 'er', 0xb6f8, 'fa', 0xb7a2, 'fan', 0xb7aa, 'fang', 0xb7bb,
'fei', 0xb7c6, 'fen', 0xb7d2, 'feng', 0xb7e1, 'fo', 0xb7f0, 'fou', 0xb7f1,
'fu', 0xb7f2, 'ga', 0xb8c1, 'gai', 0xb8c3, 'gan', 0xb8c9, 'gang', 0xb8d4,
'gao', 0xb8dd, 'ge', 0xb8e7, 'gei', 0xb8f8, 'gen', 0xb8f9, 'geng', 0xb8fb,
'gong', 0xb9a4, 'gou', 0xb9b3, 'gu', 0xb9bc, 'gua', 0xb9ce, 'guai', 0xb9d4,
'guan', 0xb9d7, 'guang', 0xb9e2, 'gui', 0xb9e5, 'gun', 0xb9f5, 'guo', 0xb9f8,
'ha', 0xb9fe, 'hai', 0xbaa1, 'han', 0xbaa8, 'hang', 0xbabb, 'hao', 0xbabe,
'he', 0xbac7, 'hei', 0xbad9, 'hen', 0xbadb, 'heng', 0xbadf, 'hong', 0xbae4,
'hou', 0xbaed, 'hu', 0xbaf4, 'hua', 0xbba8, 'huai', 0xbbb1, 'huan', 0xbbb6,
'huang', 0xbbc4, 'hui', 0xbbd2, 'hun', 0xbbe7, 'huo', 0xbbed, 'ji', 0xbbf7,
'jia', 0xbcce, 'jian', 0xbcdf, 'jiang', 0xbda9, 'jiao', 0xbdb6, 'jie', 0xbdd2,
'jin', 0xbded, 'jing', 0xbea3, 'jiong', 0xbebc, 'jiu', 0xbebe, 'ju', 0xbecf,
'juan', 0xbee8, 'jue', 0xbeef, 'jun', 0xbef9, 'ka', 0xbfa6, 'kai', 0xbfaa,
'kan', 0xbfaf, 'kang', 0xbfb5, 'kao', 0xbfbc, 'ke', 0xbfc0, 'ken', 0xbfcf,
'keng', 0xbfd3, 'kong', 0xbfd5, 'kou', 0xbfd9, 'ku', 0xbfdd, 'kua', 0xbfe4,
'kuai', 0xbfe9, 'kuan', 0xbfed, 'kuang', 0xbfef, 'kui', 0xbff7, 'kun', 0xc0a4,
'kuo', 0xc0a8, 'la', 0xc0ac, 'lai', 0xc0b3, 'lan', 0xc0b6, 'lang', 0xc0c5,
'lao', 0xc0cc, 'le', 0xc0d5, 'lei', 0xc0d7, 'leng', 0xc0e2, 'li', 0xc0e5,
'lia', 0xc1a9, 'lian', 0xc1aa, 'liang', 0xc1b8, 'liao', 0xc1c3, 'lie', 0xc1d0,
'lin', 0xc1d5, 'ling', 0xc1e1, 'liu', 0xc1ef, 'long', 0xc1fa, 'lou', 0xc2a5,
'lu', 0xc2ab, 'lv', 0xc2bf, 'luan', 0xc2cd, 'lue', 0xc2d3, 'lun', 0xc2d5,
'luo', 0xc2dc, 'ma', 0xc2e8, 'mai', 0xc2f1, 'man', 0xc2f7, 'mang', 0xc3a2,
'mao', 0xc3a8, 'me', 0xc3b4, 'mei', 0xc3b5, 'men', 0xc3c5, 'meng', 0xc3c8,
'mi', 0xc3d0, 'mian', 0xc3de, 'miao', 0xc3e7, 'mie', 0xc3ef, 'min', 0xc3f1,
'ming', 0xc3f7, 'miu', 0xc3fd, 'mo', 0xc3fe, 'mou', 0xc4b1, 'mu', 0xc4b4,
'na', 0xc4c3, 'nai', 0xc4ca, 'nan', 0xc4cf, 'nang', 0xc4d2, 'nao', 0xc4d3,
'ne', 0xc4d8, 'nei', 0xc4d9, 'nen', 0xc4db, 'neng', 0xc4dc, 'ni', 0xc4dd,
'nian', 0xc4e8, 'niang', 0xc4ef, 'niao', 0xc4f1, 'nie', 0xc4f3, 'nin', 0xc4fa,
'ning', 0xc4fb, 'niu', 0xc5a3, 'nong', 0xc5a7, 'nu', 0xc5ab, 'nv', 0xc5ae,
'nuan', 0xc5af, 'nue', 0xc5b0, 'nuo', 0xc5b2, 'o', 0xc5b6, 'ou', 0xc5b7,
'pa', 0xc5be, 'pai', 0xc5c4, 'pan', 0xc5ca, 'pang', 0xc5d2, 'pao', 0xc5d7,
'pei', 0xc5de, 'pen', 0xc5e7, 'peng', 0xc5e9, 'pi', 0xc5f7, 'pian', 0xc6aa,
'piao', 0xc6ae, 'pie', 0xc6b2, 'pin', 0xc6b4, 'ping', 0xc6b9, 'po', 0xc6c2,
'pu', 0xc6cb, 'qi', 0xc6da, 'qia', 0xc6fe, 'qian', 0xc7a3, 'qiang', 0xc7b9,
'qiao', 0xc7c1, 'qie', 0xc7d0, 'qin', 0xc7d5, 'qing', 0xc7e0, 'qiong', 0xc7ed,
'qiu', 0xc7ef, 'qu', 0xc7f7, 'quan', 0xc8a6, 'que', 0xc8b1, 'qun', 0xc8b9,
'ran', 0xc8bb, 'rang', 0xc8bf, 'rao', 0xc8c4, 're', 0xc8c7, 'ren', 0xc8c9,
'reng', 0xc8d3, 'ri', 0xc8d5, 'rong', 0xc8d6, 'rou', 0xc8e0, 'ru', 0xc8e3,
'ruan', 0xc8ed, 'rui', 0xc8ef, 'run', 0xc8f2, 'ruo', 0xc8f4, 'sa', 0xc8f6,
'sai', 0xc8f9, 'san', 0xc8fd, 'sang', 0xc9a3, 'sao', 0xc9a6, 'se', 0xc9aa,
'sen', 0xc9ad, 'seng', 0xc9ae, 'sha', 0xc9af, 'shai', 0xc9b8, 'shan', 0xc9ba,
'shang', 0xc9ca, 'shao', 0xc9d2, 'she', 0xc9dd, 'shen', 0xc9e9, 'sheng', 0xc9f9,
'shi', 0xcaa6, 'shou', 0xcad5, 'shu', 0xcadf, 'shua', 0xcba2, 'shuai', 0xcba4,
'shuan', 0xcba8,'shuang', 0xcbaa, 'shui', 0xcbad, 'shun', 0xcbb1, 'shuo', 0xcbb5,
'si', 0xcbb9, 'song', 0xcbc9, 'sou', 0xcbd1, 'su', 0xcbd4, 'suan', 0xcbe1,
'sui', 0xcbe4, 'sun', 0xcbef, 'suo', 0xcbf2, 'ta', 0xcbfa, 'tai', 0xcca5,
'tan', 0xccae, 'tang', 0xccc0, 'tao', 0xcccd, 'te', 0xccd8, 'teng', 0xccd9,
'ti', 0xccdd, 'tian', 0xccec, 'tiao', 0xccf4, 'tie', 0xccf9, 'ting', 0xccfc,
'tong', 0xcda8, 'tou', 0xcdb5, 'tu', 0xcdb9, 'tuan', 0xcdc4, 'tui', 0xcdc6,
'tun', 0xcdcc, 'tuo', 0xcdcf, 'wa', 0xcdda, 'wai', 0xcde1, 'wan', 0xcde3,
'wang', 0xcdf4, 'wei', 0xcdfe, 'wen', 0xcec1, 'weng', 0xcecb, 'wo', 0xcece,
'wu', 0xced7, 'xi', 0xcef4, 'xia', 0xcfb9, 'xian', 0xcfc6, 'xiang', 0xcfe0,
'xiao', 0xcff4, 'xie', 0xd0a8, 'xin', 0xd0bd, 'xing', 0xd0c7, 'xiong', 0xd0d6,
'xiu', 0xd0dd, 'xu', 0xd0e6, 'xuan', 0xd0f9, 'xue', 0xd1a5, 'xun', 0xd1ab,
'ya', 0xd1b9, 'yan', 0xd1c9, 'yang', 0xd1ea, 'yao', 0xd1fb, 'ye', 0xd2ac,
'yi', 0xd2bb, 'yin', 0xd2f0, 'ying', 0xd3a2, 'yo', 0xd3b4, 'yong', 0xd3b5,
'you', 0xd3c4, 'yu', 0xd3d9, 'yuan', 0xd4a7, 'yue', 0xd4bb, 'yun', 0xd4c5,
'za', 0xd4d1, 'zai', 0xd4d4, 'zan', 0xd4db, 'zang', 0xd4df, 'zao', 0xd4e2,
'ze', 0xd4f0, 'zei', 0xd4f4, 'zen', 0xd4f5, 'zeng', 0xd4f6, 'zha', 0xd4fa,
'zhai', 0xd5aa, 'zhan', 0xd5b0, 'zhang', 0xd5c1, 'zhao', 0xd5d0, 'zhe', 0xd5da,
'zhen', 0xd5e4, 'zheng', 0xd5f4, 'zhi', 0xd6a5, 'zhong', 0xd6d0, 'zhou', 0xd6db,
'zhu', 0xd6e9, 'zhua', 0xd7a5, 'zhuai', 0xd7a7, 'zhuan', 0xd7a8,'zhuang', 0xd7ae,
'zhui', 0xd7b5, 'zhun', 0xd7bb, 'zhuo', 0xd7bd, 'zi', 0xd7c8, 'zong', 0xd7d7,
'zou', 0xd7de, 'zu', 0xd7e2, 'zuan', 0xd7ea, 'zui', 0xd7ec, 'zun', 0xd7f0,
'zuo', 0xd7f2
]; // 'zuo' 结束于 0xd7f9
要能够处理更多的汉字，可以利用拼音输入法的字符表。输入法是从拼音到汉字，将其反过来使用就可以做到从汉字到拼音。
程序角度主要是如何节省存储空间和查找效率的问题。可以改进的余地应该不会太大。
最常见的应用其实就是拼音输入法。只是拼音输入法除了简单的解决单个字的问题，需要更多的发挥在词库容量和匹配效率上。
比如股票软件中根据股票名称首字母缩写查找。
TODO：查找的方法。