Submission #320649

#	Time	Username	Problem	Language	Result	Execution time	Memory
320649		monus1042	Board (CEOI13_board)	C++17	10 / 100	2 ms	748 KiB

board

// NK
#include <bits/stdc++.h>

//#include <ext/pb_ds/assoc_container.hpp>
//#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
//using namespace __gnu_pbds;

typedef pair<int,int> ii;
typedef long long ll;
typedef vector<int> vi;
typedef vector<ii> vii;
typedef vector<ll> vll;
#define pb push_back
#define eb emplace_back
#define pob pop_back
#define psf push_front
#define pof pop_front
#define mkp make_pair
#define mkt make_tuple
#define all(x) x.begin(), x.end()
#define Bolivia_is_nice ios::sync_with_stdio(false), cin.tie(nullptr)

//typedef tree<ii, null_type, less<ii>, rb_tree_tag, tree_order_statistics_node_update> ord_set;

ll locationof(string s, ll nod, ll & lev){
	for (int i=0; i<s.size(); i++){
		if (s[i] == '1'){
			nod = nod*2;
		    lev++;
		}else if (s[i] == '2'){
			nod = nod*2 + 1;
			lev++;
		}else if (s[i] == 'U'){
			nod = nod / 2;
			--lev;
		}else if (s[i] == 'L'){
			nod = nod - 1;
		}else{ // R
			nod = nod + 1;
		}
	}
	return nod;
}

vll f(ll nod){
	vll v;
	while(1){
		v.pb(nod);
		if (nod / 2 > 0){
			nod /= 2LL;
		}else break;
	}
	return v;
}

void solve(){
	string a,b; cin>>a>>b;
	ll AL = 0, BL = 0;
	ll A = locationof(a, 1ll, AL), B = locationof(b, 1ll, BL);

	//int MAXsteps = 50 * 2 + 2;
	ll Log = 52;
	if (AL < BL) swap(A, B), swap(AL, BL);
	ll ans = AL - BL;
	for (ll i = 0; i<ans; i++){
		AL--;
		A/=2LL;
	}
	//cout<<ans<<endl;
	//cout<<AL<<endl<<BL<<endl;

	if (A > B) swap(A, B);
	vll lca = f(B);
	int it = 0;
	ll curr = 0;
	ll Answer = 8e18;
	while(1){
		// first do try with current height
		if ((ll)it == (ll)lca.size()) break;
		ll HOR = lca[it] - A;
		if (HOR >= 0){
			ll temp = curr + HOR + (ll)it + ans;
			Answer = min(Answer, temp);
		}else break;

		// then climb:
		ll par = A/2;
		if (par * 2 == A && par > 0){ // A is left child
			curr++;
			A = par;
		}else if (par * 2 + 1 == A && par > 0){ // A is right child
			//move R
			bool ok = 0;
			for (ll bit = 0; bit < Log; ++bit){
				if ( (ll)((1LL << bit)-1LL) == A) ok = 1;
			}
			if (!ok){
				++curr;
				A++;
				par = A / 2;
				if (par > 0){
					++curr;
					A = par;
				}
			}else{
				break;
			}
		}else break;
		
		++it;
	}
	cout<<Answer<<'\n';
}

int main(){
	Bolivia_is_nice;
	int t = 1; //cin>>t;
	while(t--)
	solve();
	
	return 0;
}
/*
  ~/.emacs
*/

Compilation message (stderr)

board.cpp: In function 'll locationof(std::string, ll, ll&)':
board.cpp:28:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   28 |  for (int i=0; i<s.size(); i++){
      |                ~^~~~~~~~~

• Subtask 1: 0 / 10
• Subtask 2: 10 / 10
• Subtask 3: 0 / 10
• Subtask 4: 0 / 10
• Subtask 5: 0 / 10
• Subtask 6: 0 / 10
• Subtask 7: 0 / 10
• Subtask 8: 0 / 10
• Subtask 9: 0 / 10
• Subtask 10: 0 / 10