View Compilation Error

0_0_33580211_20318.cpp: In function 'int main()':
0_0_33580211_20318.cpp:16:2: error: 'cin' was not declared in this scope
  cin>>t;
  ^
0_0_33580211_20318.cpp:22:33: error: 'scanf' was not declared in this scope
    scanf("%d %d",&a[i].p,&a[i].a);
                                 ^
0_0_33580211_20318.cpp:64:20: error: 'printf' was not declared in this scope
   printf("%d\n",ans);
                    ^