View Compilation Error

551385_0_0_18880.cpp: In function `bool is_const_num(char*, int)':
551385_0_0_18880.cpp:50: error: `i' undeclared (first use this function)
551385_0_0_18880.cpp:50: error: (Each undeclared identifier is reported only once for each function it appears in.)
551385_0_0_18880.cpp: In function `bool cal(char*, int)':
551385_0_0_18880.cpp:45: error: too few arguments to function `bool is_identifier(char*, int)'
551385_0_0_18880.cpp:76: error: at this point in file
551385_0_0_18880.cpp:49: error: too few arguments to function `bool is_const_num(char*, int)'
551385_0_0_18880.cpp:82: error: at this point in file