View Compilation Error

0_0_21593445_8084.cpp:20:18: error: stray '#' in program
   k=k*10+str[i]-'0';
                  ^
0_0_21593445_8084.cpp:20:24: error: stray '#' in program
   k=k*10+str[i]-'0';
                        ^
0_0_21593445_8084.cpp: In function 'void dfs(long long int, long long int)':
0_0_21593445_8084.cpp:20:19: error: lvalue required as unary '&' operand
   k=k*10+str[i]-'0';
                   ^