View Compilation Error

0_0_19648943_18950.cpp: In function 'int main()':
0_0_19648943_18950.cpp:24:21: error: 'scanf' was not declared in this scope
  while(scanf("%d",&n)!=EOF&&n!=0)
                     ^
0_0_19648943_18950.cpp:24:24: error: 'EOF' was not declared in this scope
  while(scanf("%d",&n)!=EOF&&n!=0)
                        ^
0_0_19648943_18950.cpp:41:25: error: 'printf' was not declared in this scope
   printf("%.2lf\n",min/2);
                         ^