View Compilation Error

0_0_35953677_21456.cpp: In function 'void init()':
0_0_35953677_21456.cpp:9:55: error: 'memset' was not declared in this scope
     memset(fatherRootNumber,0,sizeof(fatherRootNumber));
                                                       ^
0_0_35953677_21456.cpp: In function 'int main()':
0_0_35953677_21456.cpp:39:30: error: 'scanf' was not declared in this scope
     while(scanf("%d %d",&a,&b) != EOF && (a >= 0) && (b >= 0))
                              ^
0_0_35953677_21456.cpp:39:35: error: 'EOF' was not declared in this scope
     while(scanf("%d %d",&a,&b) != EOF && (a >= 0) && (b >= 0))
                                   ^
0_0_35953677_21456.cpp:58:50: error: 'printf' was not declared in this scope
                 printf("Case %d is a tree.\n",k++);
                                                  ^
0_0_35953677_21456.cpp:60:54: error: 'printf' was not declared in this scope
                 printf("Case %d is not a tree.\n",k++);
                                                      ^