View Compilation Error

0_0_20495600_12349.cpp: In function 'void build(int, int, int, int)':
0_0_20495600_12349.cpp:36:25: error: 'push_up' was not declared in this scope
     push_up(u, l, r, dep);
                         ^
0_0_20495600_12349.cpp: In function 'int getR(int, int, int)':
0_0_20495600_12349.cpp:124:20: error: 'n' was not declared in this scope
     int l = 0, r = n + 1, m;
                    ^
0_0_20495600_12349.cpp:128:9: error: 'm' was not declared in this scope
         m = l + (r - l) / 2;
         ^