View Compilation Error

0_0_20127516_31057.cpp: In function 'int main()':
0_0_20127516_31057.cpp:8:13: error: 'get' was not declared in this scope
  while(get(a)!="+")
             ^
0_0_20127516_31057.cpp:12:21: error: 'strcmp' was not declared in this scope
     if(strcmp(a,b[i])==0) 
                     ^
0_0_20127516_31057.cpp:21:13: error: 'get' was not declared in this scope
  while(get(a)=="+")
             ^
0_0_20127516_31057.cpp:28:21: error: 'strcmp' was not declared in this scope
     if(strcmp(a,b[i])==0) 
                     ^