View Compilation Error

0_0_21047432_7841.cpp: In function 'int main()':
0_0_21047432_7841.cpp:24:24: error: cannot pass objects of non-trivially-copyable type 'std::string {aka class std::basic_string<char>}' through '...'
    while(scanf("%s",str) not_eq EOF){
                        ^
0_0_21047432_7841.cpp:25:27: error: cannot convert 'std::string {aka std::basic_string<char>}' to 'const char*' for argument '1' to 'size_t strlen(const char*)'
         int len=strlen(str);
                           ^
0_0_21047432_7841.cpp:28:13: error: 'LL' was not declared in this scope
             LL n=0;bool flag=0;
             ^
0_0_21047432_7841.cpp:29:35: error: 'n' was not declared in this scope
             for(int i=0;i<len;i++)n=n*10+str[i]-'0';
                                   ^
0_0_21047432_7841.cpp:31:17: error: 'n' was not declared in this scope
                 n=sqrt(n);
                 ^
0_0_21047432_7841.cpp:32:22: error: expected ')' before 'eq'
                 if(n eq 1){flag=1;print(i);break;}
                      ^
0_0_21047432_7841.cpp:32:42: error: 'print' was not declared in this scope
                 if(n eq 1){flag=1;print(i);break;}
                                          ^