View Compilation Error

0_0_16194803_25324.cpp: In function 'int main()':
0_0_16194803_25324.cpp:6:18: error: 'scanf' was not declared in this scope
     scanf("%d",&n);
                  ^
0_0_16194803_25324.cpp:8:13: error: 'getchar' was not declared in this scope
     getchar();
             ^
0_0_16194803_25324.cpp:11:13: error: 'gets' was not declared in this scope
     gets(str);
             ^
0_0_16194803_25324.cpp:14:18: error: 'printf' was not declared in this scope
     printf("no\n");
                  ^
0_0_16194803_25324.cpp:23:23: error: 'printf' was not declared in this scope
         printf("yes\n");
                       ^
0_0_16194803_25324.cpp:25:22: error: 'printf' was not declared in this scope
         printf("no\n");
                      ^