View Compilation Error

0_0_38549283_5167.cpp: In function 'void push_down(int)':
0_0_38549283_5167.cpp:21:31: error: 'swap' was not declared in this scope
     swap(tr[k].s[1],tr[k].s[0]);
                               ^
0_0_38549283_5167.cpp: In function 'int main()':
0_0_38549283_5167.cpp:71:22: error: 'scanf' was not declared in this scope
         scanf("%d",&n);
                      ^
0_0_38549283_5167.cpp:73:31: error: 'memset' was not declared in this scope
         memset(tr,0,sizeof(tr));
                               ^
0_0_38549283_5167.cpp:80:27: error: 'sort' was not declared in this scope
         sort(a+1,a+n+3,cmp);
                           ^
0_0_38549283_5167.cpp:86:31: error: 'printf' was not declared in this scope
             printf("%d ",ans-1);
                               ^
0_0_38549283_5167.cpp:89:24: error: 'printf' was not declared in this scope
         printf("%d\n",n);
                        ^