View Compilation Error

0_0_21591168_28942.cpp:44:23: error: stray '#' in program
             a=str[0]-'a'+1;
                       ^
0_0_21591168_28942.cpp:44:29: error: stray '#' in program
             a=str[0]-'a'+1;
                             ^
0_0_21591168_28942.cpp:45:35: error: stray '#' in program
             b=str[strlen(str)-1]-'a'+1;
                                   ^
0_0_21591168_28942.cpp:45:41: error: stray '#' in program
             b=str[strlen(str)-1]-'a'+1;
                                         ^
0_0_21591168_28942.cpp: In function 'int main()':
0_0_21591168_28942.cpp:44:24: error: lvalue required as unary '&' operand
             a=str[0]-'a'+1;
                        ^
0_0_21591168_28942.cpp:45:36: error: lvalue required as unary '&' operand
             b=str[strlen(str)-1]-'a'+1;
                                    ^