模拟实现WORD中“查找/替换”功能。程序结构的主要功能有三个：1.文件的打开与读写2.文件中单词的查找3.文件中单词的替换 -Simulation realize WORD "search/replace" function. The main function of the program structure are three: 1. The file open and reading and writing 2. File of words search 3. File of wor