View Compilation Error

0_0_14561261_6065.cpp: In function 'int main()':
0_0_14561261_6065.cpp:9:14: error: 'gets' was not declared in this scope
  while(gets(c))
              ^
0_0_14561261_6065.cpp:21:23: error: 'sprintf' was not declared in this scope
     sprintf(a,"%d",sum);
                       ^
0_0_14561261_6065.cpp:29:21: error: 'printf' was not declared in this scope
    printf("%d\n",sum);
                     ^