View Compilation Error

0_0_14301780_32301.cpp: In function 'int main()':
0_0_14301780_32301.cpp:22:18: error: cannot pass objects of non-trivially-copyable type 'std::string {aka class std::basic_string<char>}' through '...'
    scanf("%s",str);
                  ^
0_0_14301780_32301.cpp:42:27: error: cannot pass objects of non-trivially-copyable type 'std::string {aka class std::basic_string<char>}' through '...'
             scanf("%s",str);
                           ^