View Compilation Error

0_0_24400025_9964.cpp: In function 'double prim(int)':
0_0_24400025_9964.cpp:9:38: error: 'memset' was not declared in this scope
 #define mem(a,b) memset(a,b,sizeof(a))
                                      ^
0_0_24400025_9964.cpp:29:5: note: in expansion of macro 'mem'
     mem(vis, 0);
     ^
0_0_24400025_9964.cpp: In function 'int main()':
0_0_24400025_9964.cpp:57:21: error: 'scanf' was not declared in this scope
     scanf("%d", &cas);
                     ^
0_0_24400025_9964.cpp:66:77: error: 'sqrt' was not declared in this scope
                 dis = sqrt( sqr(p[i][1] - p[j][1]) + sqr(p[i][2] - p[j][2]) );
                                                                             ^
0_0_24400025_9964.cpp:73:37: error: 'printf' was not declared in this scope
         if (ans > oo) printf("oh!\n"); else printf("%.1lf\n", ans);
                                     ^
0_0_24400025_9964.cpp:73:66: error: 'printf' was not declared in this scope
         if (ans > oo) printf("oh!\n"); else printf("%.1lf\n", ans);
                                                                  ^