View Compilation Error

0_0_11694861_6902.cpp: In function `void Maketree(int, int)':
0_0_11694861_6902.cpp:101: error: `to' undeclared (first use this function)
0_0_11694861_6902.cpp:101: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_11694861_6902.cpp: In function `void build(int, int)':
0_0_11694861_6902.cpp:114: error: `next' undeclared (first use this function)
0_0_11694861_6902.cpp:115: error: `to' undeclared (first use this function)
0_0_11694861_6902.cpp: In function `int main()':
0_0_11694861_6902.cpp:196: error: `add' undeclared (first use this function)
0_0_11694861_6902.cpp:199: error: `get_son_dep' undeclared (first use this function)