View Compilation Error

0_0_21200813_22747.cpp: In function 'int main()':
0_0_21200813_22747.cpp:49:15: error: 'scanf' was not declared in this scope
  scanf("%d",&T);
               ^
0_0_21200813_22747.cpp:53:27: error: 'printf' was not declared in this scope
   printf("%d\n",solve(n,k));
                           ^