Submission #462509

#	Time	Username	Problem	Language	Result	Execution time	Memory
462509		arwaeystoamneg	Building 4 (JOI20_building4)	C++17	0 / 100	2 ms	460 KiB

building4

// EXPLOSION!
#define _CRT_SECURE_NO_WARNINGS
#include<bits/stdc++.h>
#include<unordered_set>
#include<unordered_map>
#include<chrono>

using namespace std;
typedef pair<int, int> pii;
typedef long long ll;
typedef pair<ll, ll> pll;
typedef long double ld;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<pair<int, int>> vpi;
typedef vector<pair<ll, ll>> vpll;

#define FOR(i,a,b) for (int i = (a); i < (b); ++i)
#define F0R(i,a) FOR(i,0,a)
#define ROF(i,a,b) for (int i = (b)-1; i >= (a); --i)
#define R0F(i,a) ROF(i,0,a)
#define trav(a,x) for (auto& a: x)

#define pb push_back
#define mp make_pair
#define rsz resize
#define sz(x) int(x.size())
#define all(x) x.begin(),x.end()
#define f first
#define s second
#define cont continue
//#define endl '\n'
//#define ednl '\n'
#define test int testc;cin>>testc;while(testc--)
#define pr(a, b) trav(x,a)cerr << x << b; cerr << endl;
#define message cout << "Hello World" << endl;
const int dx[4] = { 1,0,-1,0 }, dy[4] = { 0,1,0,-1 }; // for every grid problem!!
const ll linf = 4000000000000000000LL;
const ll inf = 1000000007;//998244353    

void pv(vi a) { trav(x, a)cout << x << " "; cout << endl; }void pv(vll a) { trav(x, a)cout << x << " "; cout << endl; }void pv(vector<vi>a) {
	F0R(i, sz(a)) { cout << i << endl; pv(a[i]); cout << endl; }
}void pv(vector<vll>a) { F0R(i, sz(a)) { cout << i << endl; pv(a[i]); }cout << endl; }void pv(vector<string>a) { trav(x, a)cout << x << endl; cout << endl; }
void setIO(string s) {
	ios_base::sync_with_stdio(0); cin.tie(0);
#ifdef arwaeystoamneg
	if (sz(s))
	{
		freopen((s + ".in").c_str(), "r", stdin);
		if (s != "test1")
			freopen((s + ".out").c_str(), "w", stdout);
	}
#endif
}
struct T
{
	int a, b;
	void operator+=(const T& x)
	{
		a = min(a, x.a);
		b = max(b, x.b);
	}
	T()
	{
		a = inf, b = -inf;
	}
	T(int x, int y)
	{
		a = x, b = y;
	}
	T operator+(int x)const
	{
		T res = T(a, b);
		res.a += x, res.b += x;
		return res;
	}
	bool check(int x)
	{
		return a <= x && x <= b;
	}
};
int n;
vi a, b;
int main()
{
	setIO("test1");
	cin >> n;
	a.rsz(2 * n);
	b.rsz(2 * n);
	trav(x, a)cin >> x;
	trav(x, b)cin >> x;
	a.pb(inf);
	b.pb(inf);
	vector<T> A(2 * n + 1), B(2 * n + 1);
	A[0] = T(1, 1);
	B[0] = T(0, 0);
	F0R(i, 2 * n)
	{
		// A -> A
		if (a[i] <= a[i + 1])
			A[i + 1] += (A[i] + 1);
		// A -> B
		if (a[i] <= b[i + 1])
			B[i + 1] += A[i];
		// B -> A
		if (b[i] <= a[i + 1])
			A[i + 1] += (B[i] + 1);
		// B -> B
		if (b[i] <= b[i + 1])
			B[i + 1] += B[i];
	}
	if (min(A[2 * n].a, B[2 * n].a) > n || n > max(A[2 * n].b, B[2 * n].b))
	{
		cout << -1 << endl;
		return 0;
	}
	int pos = 'A', c = n;
	if (A[2 * n].check(n))pos = 'B';
	string ans = "";
	R0F(i, 2 * n)
	{
		ans.pb(pos);
		if (pos == 'A')
		{
			if (a[i] <= a[i + 1])
			{
				if ((A[i] + 1).check(c))
				{

				}
				else
				{
					pos = 'B';
				}
			}
			else
			{
				pos = 'B';
			}
			c--;
		}
		else
		{
			if (a[i] <= b[i + 1])
			{
				if ((A[i]).check(c))
				{
					pos = 'A';
				}
			}
			else
			{
			}
		}
	}
	ans.pb(pos);
	reverse(all(ans));
	ans.pop_back();
	cout << ans << endl;
}

• Subtask 1: 0 / 11
• Subtask 2: 0 / 89