．任意個連續的字符組成的子序列
．
O(m+n)
．
．
．()模式匹配 ()模式串
．()其數據元素都是字符()順序存儲()和鏈式存儲()串的長度相等且兩串中對應位置的字符也相等
．兩串的長度相等且兩串中對應位置的字符也相等
．xyxyxywwy
．*s++=*t++ 或（*s++=*t++）!=\
．（）char s[ ] () j++ () i >= j
[] [] [] [] [] [] [] [] [] [] [] [] [] [] [] [] [] [] [] [] [] []
From:http://tw.wingwit.com/Article/program/sjjg/201311/22617.html
