View Compilation Error

0_0_2872125_4059.cpp: In function `int getint()':
0_0_2872125_4059.cpp:42: error: `isdigit' undeclared (first use this function)
0_0_2872125_4059.cpp:42: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_2872125_4059.cpp: In member function `void Splay_Tree::update(NODE*)':
0_0_2872125_4059.cpp:81: error: `max' undeclared (first use this function)
0_0_2872125_4059.cpp: In member function `int Splay_Tree::getval(int)':
0_0_2872125_4059.cpp:117: error: `max' undeclared (first use this function)