View Compilation Error

0_0_6655731_19314.cpp: In function `void make_tree(int, int, int)':
0_0_6655731_19314.cpp:7: error: `tree' undeclared (first use this function)
0_0_6655731_19314.cpp:7: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_6655731_19314.cpp:12: error: `L' undeclared (first use this function)
0_0_6655731_19314.cpp:13: error: `R' undeclared (first use this function)
0_0_6655731_19314.cpp: In function `void insert(int, int, int)':
0_0_6655731_19314.cpp:17: error: `tree' undeclared (first use this function)
0_0_6655731_19314.cpp:23: error: `L' undeclared (first use this function)
0_0_6655731_19314.cpp:25: error: `R' undeclared (first use this function)