ZOJ的编译器很不习惯。经常出现编译错误。很多时候是因为缺少头文件 我也懒得记那个函数要用到哪个头文件。常用的都写上就OK了: #include "cstdlib" #include "cctype" #include "cstring" #include "cstdio" #include "cmath" #include "algorithm" #include "vector" #include "string" #include "iostream" #include "sstream" #include "set" #include "queue" #include "stack" #include "fstream" #include "iomanip" #include "bitset" #include "list" #include "ctime" using namespace std;