View Compilation Error

0_0_32666801_25616.cpp: In function 'int main()':
0_0_32666801_25616.cpp:3:39: error: 'scanf' was not declared in this scope
     while(scanf("%f%f%f%f",&a,&b,&c,&d)!=EOF)
                                       ^
0_0_32666801_25616.cpp:3:42: error: 'EOF' was not declared in this scope
     while(scanf("%f%f%f%f",&a,&b,&c,&d)!=EOF)
                                          ^
0_0_32666801_25616.cpp:5:53: error: 'sqrt' was not declared in this scope
         printf("%.2f\n",sqrt((a-c)*(a-c)+(b-d)*(b-d)));
                                                     ^
0_0_32666801_25616.cpp:5:54: error: 'printf' was not declared in this scope
         printf("%.2f\n",sqrt((a-c)*(a-c)+(b-d)*(b-d)));
                                                      ^