View Compilation Error

0_0_23385214_10893.cpp: In function 'int main()':
0_0_23385214_10893.cpp:7:25: error: 'scanf' was not declared in this scope
     while(~scanf("%d",&n))
                         ^
0_0_23385214_10893.cpp:9:17: error: 'getchar' was not declared in this scope
         getchar();
                 ^
0_0_23385214_10893.cpp:12:19: error: 'gets' was not declared in this scope
             gets(a);
                   ^
0_0_23385214_10893.cpp:19:41: error: 'printf' was not declared in this scope
             if(j==length) printf("yes\n");
                                         ^
0_0_23385214_10893.cpp:20:40: error: 'printf' was not declared in this scope
             else          printf("no\n");
                                        ^