View Compilation Error

0_0_31850955_14871.cpp: In function 'void build(int&, int, int)':
0_0_31850955_14871.cpp:24:14: error: expected ')' at end of input
     if (l == r
              ^
0_0_31850955_14871.cpp:24:14: error: expected statement at end of input
0_0_31850955_14871.cpp:24:14: error: expected '}' at end of input