BT文件快速解析算法

要想實現一個BT下載器,第一步就是解析bt文件:

d 
        8:announce 37:http://tracker.ktxp.com:6868/announce
        13:announce-list
        l
                l 37:http://tracker.ktxp.com:6868/announce e
                l 37:http://tracker.ktxp.com:7070/announce e
                l 36:udp://tracker.ktxp.com:6868/announce e
                l 36:udp://tracker.ktxp.com:7070/announce e
                l 37:http://tracker.dmhy.org:8000/announce e
                l 36:udp://tracker.dmhy.org:8000/announce e
                l 45:http://tracker.openbittorrent.com:80/announce e
                l 39:http://tracker.publicbt.com:80/announce e
                l 30:http://tracker.prq.to/announce e
                l 36:http://bt.titapark.com:2710/announce e
                l 33:http://bt.wiiyi.com:6969/announce e
                l 32:http://bt.dmzg.net:6969/announce e
                l 34:http://bt.levelup.cn:8080/announce e
                l 34:http://bt.levelup.cn