View Compilation Error

0_0_33142165_12853.cpp: In function 'void update(int, int)':
0_0_33142165_12853.cpp:21:19: error: cannot convert 'value_segment_tree' to 'int' in initialization
  int l = tree[root]
                   ^
0_0_33142165_12853.cpp:21:19: error: expected ',' or ';' at end of input
0_0_33142165_12853.cpp:21:19: error: expected '}' at end of input