View Compilation Error

0_0_21601401_30589.cpp:37:26: error: stray '#' in program
         root.sum=ch[le]-'0';
                          ^
0_0_21601401_30589.cpp:37:32: error: stray '#' in program
         root.sum=ch[le]-'0';
                                ^
0_0_21601401_30589.cpp: In function 'void build_tree(int, int, int)':
0_0_21601401_30589.cpp:37:27: error: lvalue required as unary '&' operand
         root.sum=ch[le]-'0';
                           ^