#include <iostream> #include <vector> #include <string> #include <cstring> #define MAX 10000 using namespace std; int tree[MAX]; void preverse(int x) { cout<<tree[x]<<" "; if(tree[2*x+1] != 0) preverse(2*x+1); if(tree[2*x+2] != 0) preverse(2*x+2); } void midverse(int x) { if(tree[2*x+1] != 0) midverse(2*x+1); cout<<tree[x]<<" "; if(tree[2*x+2] != 0) midverse(2*x+2); } void deverse(int x) { if(tree[2*x+1] != 0) deverse(2*x+1); if(tree[2*x+2] != 0) deverse(2*x+2); cout<<tree[x]<<" "; } int main() { int n; cin>>n; for (int i = 0; i < n; ++i) { cin>>tree[i]; } preverse(0); cout<<endl; midverse(0); cout<<endl; deverse(0); return 0; }