View Compilation Error

0_0_20253485_28362.cpp: In function 'int main()':
0_0_20253485_28362.cpp:92:5: error: 'set' was not declared in this scope
     set<int> s;
     ^
0_0_20253485_28362.cpp:92:9: error: expected primary-expression before 'int'
     set<int> s;
         ^
0_0_20253485_28362.cpp:106:13: error: 's' was not declared in this scope
             s.insert(p - 1);
             ^
0_0_20253485_28362.cpp:126:18: error: expected primary-expression before 'int'
         for (set<int>::iterator it = s.begin(); it != s.end(); it++)
                  ^
0_0_20253485_28362.cpp:126:49: error: 'it' was not declared in this scope
         for (set<int>::iterator it = s.begin(); it != s.end(); it++)
                                                 ^
0_0_20253485_28362.cpp:126:55: error: 's' was not declared in this scope
         for (set<int>::iterator it = s.begin(); it != s.end(); it++)
                                                       ^
0_0_20253485_28362.cpp:131:9: error: 's' was not declared in this scope
         s.clear();
         ^