View Compilation Error

0_0_25236253_30907.cpp: In function 'int main()':
0_0_25236253_30907.cpp:61:21: error: 'strcmp' was not declared in this scope
   if(strcmp(ch, "GT") == 0)
                     ^
0_0_25236253_30907.cpp:80:20: error: 'strcmp' was not declared in this scope
   if(strcmp(ch,"AP") == 0)
                    ^
0_0_25236253_30907.cpp:94:20: error: 'strcmp' was not declared in this scope
   if(strcmp(ch,"MG") == 0)
                    ^