View Compilation Error

0_0_19767369_21267.cpp: In function 'int main()':
0_0_19767369_21267.cpp:8:18: error: 'scanf' was not declared in this scope
  scanf("%d%*c",&n);
                  ^
0_0_19767369_21267.cpp:12:9: error: 'gets' was not declared in this scope
   gets(c);
         ^
0_0_19767369_21267.cpp:25:25: error: 'printf' was not declared in this scope
   if(b==1)printf("Yes\n");
                         ^
0_0_19767369_21267.cpp:27:17: error: 'printf' was not declared in this scope
    printf("No\n");   
                 ^