foo.cc:7:12: error: 'string' was not declared in this scope
 bool judge(string s1, string s2, string s3){
            ^~~~~~
foo.cc:7:12: note: suggested alternative: 'stdin'
 bool judge(string s1, string s2, string s3){
            ^~~~~~
            stdin
foo.cc:7:23: error: 'string' was not declared in this scope
 bool judge(string s1, string s2, string s3){
                       ^~~~~~
foo.cc:7:23: note: suggested alternative: 'stdin'
 bool judge(string s1, string s2, string s3){
                       ^~~~~~
                       stdin
foo.cc:7:34: error: 'string' was not declared in this scope
 bool judge(string s1, string s2, string s3){
                                  ^~~~~~
foo.cc:7:34: note: suggested alternative: 'stdin'
 bool judge(string s1, string s2, string s3){
                                  ^~~~~~
                                  stdin
foo.cc:7:43: error: expression list treated as compound expression in initializer [-fpermissive]
 bool judge(string s1, string s2, string s3){
                                           ^
foo.cc: In function 'int main()':
foo.cc:19:5: error: 'string' was not declared in this scope
     string s1, s2, s3;
     ^~~~~~
foo.cc:19:5: note: suggested alternative: 'stdin'
     string s1, s2, s3;
     ^~~~~~
     stdin
foo.cc:20:5: error: 'cin' was not declared in this scope
     cin >> n;
     ^~~
foo.cc:20:5: note: suggested alternative: 'main'
     cin >> n;
     ^~~
     main
foo.cc:21:12: error: 's1' was not declared in this scope
     cin >> s1 >> s2 >> s3;
            ^~
foo.cc:21:18: error: 's2' was not declared in this scope
     cin >> s1 >> s2 >> s3;
                  ^~
foo.cc:21:24: error: 's3' was not declared in this scope
     cin >> s1 >> s2 >> s3;
                        ^~
foo.cc:22:23: error: 'judge' cannot be used as a function
     if(judge(s1,s2, s3)){
                       ^
foo.cc:24:9: error: 'cout' was not declared in this scope
         cout << s1 << endl;
         ^~~~
foo.cc:24:23: error: 'endl' was not declared in this scope
         cout << s1 << endl;
                       ^~~~
foo.cc:24:23: note: suggested alternative: 'enum'
         cout << s1 << endl;
                       ^~~~
                       enum
foo.cc:26:28: error: 'judge' cannot be used as a function
     else if(judge(s2,s1, s3)){
                            ^
foo.cc:28:9: error: 'cout' was not declared in this scope
         cout << s2 << endl;
         ^~~~
foo.cc:28:23: error: 'endl' was not declared in this scope
         cout << s2 << endl;
                       ^~~~
foo.cc:28:23: note: suggested alternative: 'enum'
         cout << s2 << endl;
                       ^~~~
                       enum
foo.cc:30:28: error: 'judge' cannot be used as a function
     else if(judge(s3,s1, s2)){
                            ^
foo.cc:32:9: error: 'cout' was not declared in this scope
         cout << s3 << endl;
         ^~~~
foo.cc:32:23: error: 'endl' was not declared in this scope
         cout << s3 << endl;
                       ^~~~
foo.cc:32:23: note: suggested alternative: 'enum'
         cout << s3 << endl;
                       ^~~~
                       enum