View Compilation Error

0_0_29403261_17778.cpp: In function 'void Stack()':
0_0_29403261_17778.cpp:16:27: error: 'strcmp' was not declared in this scope
         if (!strcmp(c,"IN"))
                           ^
0_0_29403261_17778.cpp: In function 'void Queue()':
0_0_29403261_17778.cpp:39:27: error: 'strcmp' was not declared in this scope
         if (!strcmp(c,"IN"))
                           ^
0_0_29403261_17778.cpp: In function 'int main()':
0_0_29403261_17778.cpp:58:30: error: 'strcmp' was not declared in this scope
         if (!strcmp(c, "FIFO")) Queue();
                              ^