View Compilation Error

0_0_23639115_10621.cpp: In function 'void dfs(int, int)':
0_0_23639115_10621.cpp:12:28: error: 'printf' was not declared in this scope
         printf("%d: ",++sum);
                            ^
0_0_23639115_10621.cpp: In function 'int main()':
0_0_23639115_10621.cpp:34:29: error: 'memset' was not declared in this scope
         memset(g,0,sizeof(g));
                             ^
0_0_23639115_10621.cpp:37:36: error: 'scanf' was not declared in this scope
             scanf("%d%d%d",&x,&y,&z);
                                    ^
0_0_23639115_10621.cpp:39:29: error: 'sort' was not declared in this scope
             sort(g[i],g[i]+3);
                             ^
0_0_23639115_10621.cpp:41:28: error: 'scanf' was not declared in this scope
         while(scanf("%d",&n)&&n)
                            ^