Submission #94401

# Submission time Handle Problem Language Result Execution time Memory
94401 2019-01-18T04:21:40 Z qkxwsm Mountain Trek Route (IZhO12_route) C++14
100 / 100
356 ms 50368 KB
#pragma GCC optimize ("O3")
#pragma GCC target ("sse4")
#include <bits/stdc++.h>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/rope>

using namespace std;
using namespace __gnu_pbds;
using namespace __gnu_cxx;

random_device(rd);
mt19937 rng(rd());
const long long FIXED_RANDOM = chrono::steady_clock::now().time_since_epoch().count();

struct custom_hash
{
	template<class T>
	unsigned long long operator()(T v) const
	{
		unsigned long long x = v;
		x += FIXED_RANDOM;
		// x += 11400714819323198485ull;
		// x = (x ^ (x >> 30)) * 13787848793156543929ull;
		x = (x ^ (x >> 27)) * 10723151780598845931ull;
		return x ^ (x >> 31);
	}
};

template<class T> using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
template<class T, class U> using hash_table = gp_hash_table<T, U, custom_hash>;

template<class T>
T randomize(T mod)
{
	return (uniform_int_distribution<T>(0, mod - 1))(rng);
}
template<class T>
void readi(T &x)
{
	x = 0;
	bool negative = false;
	char c = ' ';
	while (c < '-')
	{
		c = getchar();
	}
	if (c == '-')
	{
		negative = true;
		c = getchar();
	}
	while (c >= '0')
	{
		x = x * 10 + (c - '0');
		c = getchar();
	}
	if (negative)
	{
		x = -x;
	}
}
template<class T>
void printi(T output)
{
	if (output == 0)
	{
		putchar('0');
		return;
	}
	if (output < 0)
	{
		putchar('-');
		output = -output;
	}
	int buf[20], n = 0;
	while(output)
	{
		buf[n] = ((output % 10));
		output /= 10;
		n++;
	}
	for (n--; n >= 0; n--)
	{
		putchar(buf[n] + '0');
	}
	return;
}
template<class T>
void ckmin(T &a, T b)
{
	a = min(a, b);
}
template<class T>
void ckmax(T &a, T b)
{
	a = max(a, b);
}
long long expo(long long a, long long e, long long mod)
{
	return ((e == 0) ? 1 : ((expo(a * a % mod, e >> 1, mod)) * ((e & 1) ? a : 1) % mod));
}
template<class T, class U>
void nmod(T &x, U mod)
{
	if (x >= mod) x -= mod;
}
template<class T>
T gcd(T a, T b)
{
	return (b ? gcd(b, a % b) : a);
}

#define y0 ___y0
#define y1 ___y1
#define MP make_pair
#define PB push_back
#define LB lower_bound
#define UB upper_bound
#define fi first
#define se second
#define DBG(x) cerr << #x << " = " << (x) << endl
#define SZ(x) ((int) ((x).size()))
#define FOR(i, a, b) for (auto i = (a); i < (b); i++)
#define FORD(i, a, b) for (auto i = (a) - 1; i >= (b); i--)
#define ALL(x) (x).begin(), (x).end()

const long double PI = 4.0 * atan(1.0);
const long double EPS = 1e-9;

#define MAGIC 347
#define SINF 10007
#define CO 1000007
#define INF 1000000007
#define BIG 1000000931
#define LARGE 1696969696967ll
#define GIANT 2564008813937411ll
#define LLINF 2696969696969696969ll

typedef long long ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef pair<ld, ld> pdd;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef vector<ld> vd;
typedef vector<pii> vpi;
typedef vector<pll> vpl;
typedef vector<pdd> vpd;

int N;
ll K;
vpl arr, cur;
ll ans;

pll go(int x)
{
	//# of moves, return!
	pll res = {0, 0}; cur.clear();
	for (pll p : arr)
	{
		while(SZ(cur) >= 2)
		{
			pll q = cur.back(); cur.pop_back();
			if (q.fi > p.fi && q.fi > cur.back().fi && q.se <= x)
			{
				if (p.fi > cur.back().fi)
				{
					cur.PB({p.fi, q.se});
					res.fi += (q.fi - p.fi) * (q.se);
					res.se += (q.fi - p.fi);
				}
				else
				{
					cur.back().se += q.se;
					res.fi += (q.fi - cur.back().fi) * (q.se);
					res.se += (q.fi - cur.back().fi);
				}
			}
			else
			{
				cur.PB(q);
				break;
			}
		}
		if (cur.empty() || cur.back().fi != p.fi)
		{
			cur.PB(p);
		}
		else
		{
			cur.back().se += p.se;
		}
	}
	return res;
}

int32_t main()
{
	ios_base::sync_with_stdio(0); cin.tie(0);
	// cout << fixed << setprecision(10);
	// cerr << fixed << setprecision(10);
	// if (fopen("file.in", "r"))
	// {
	// 	freopen ("file.in", "r", stdin);
	// 	freopen ("file.out", "w", stdout);
	// }
	cin >> N >> K;
	FOR(i, 0, N)
	{
		ll x; cin >> x;
		arr.PB({x, 1});
	}
	ll mx = 0;
	FOR(i, 0, N)
	{
		if (arr[i].fi > arr[mx].fi)
		{
			mx = i;
		}
	}
	// DBG(mx);
	rotate(arr.begin(), arr.begin() + mx, arr.end());
	reverse(ALL(arr));
	// FOR(i, 0, N)
	// {
	// 	cerr << arr[i].fi << ' ';
	// }
	// cerr << endl;
	while(SZ(arr) > 1 && arr[SZ(arr) - 2].fi == arr[SZ(arr) - 1].fi)
	{
		arr.pop_back();
	}
	reverse(ALL(arr));
	mx = arr[0].fi;
	if (arr.back().fi == mx) arr.pop_back();
	FOR(i, 1, SZ(arr))
	{
		arr[i].fi = arr[0].fi - arr[i].fi;
	}
	arr[0].fi = 0;
	arr.PB({0, 1});
	// FOR(i, 0, SZ(arr))
	// {
	// 	cerr << arr[i].fi << ' ' << arr[i].se << endl;
	// }
	FOR(i, 0, SZ(arr))
	{
		if (cur.empty() || arr[i].fi != cur.back().fi)
		{
			cur.PB(arr[i]);
		}
		else
		{
			cur.back().se += arr[i].se;
		}
	}
	arr = cur;
	// cerr << "original\n";
	// FOR(i, 0, SZ(arr))
	// {
	// 	cerr << arr[i].fi << ' ' << arr[i].se << endl;
	// }
	//binary serach on: we'll take moves that cost x, how long does it take us?
	pll p = go(N);
	if (p.fi < K)
	{
		cout << p.se * 2 << '\n';
		return 0;
	}
	ll lo = 1, hi = N;
	while(hi > lo)
	{
		int mid = (hi + lo) >> 1;
		pll p = go(mid);
		if (p.fi >= K) hi = mid;
		else lo = mid + 1;
	}
	p = go(lo);
	ans = 2 * (p.se - ((p.fi - K + lo - 1) / lo));
	cout << ans << '\n';
	// FOR(i, 0, N)
	// {
	// 	cerr << arr[i].fi << ' ';
	// }
	// cerr << endl;
	// cerr << "time elapsed = " << (clock() / (CLOCKS_PER_SEC / 1000)) << " ms" << endl;
	return 0;
}
/* READ READ READ
* int overflow, maxn too small, special cases (n=1?, two distinct?), cin.tie() interactive
* reread the problem, try small cases
* note down possible sources of error as you go
* do smth instead of nothing
*/
# Verdict Execution time Memory Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 2 ms 376 KB Output is correct
3 Correct 2 ms 376 KB Output is correct
4 Correct 2 ms 376 KB Output is correct
5 Correct 2 ms 380 KB Output is correct
6 Correct 2 ms 376 KB Output is correct
7 Correct 2 ms 376 KB Output is correct
8 Correct 2 ms 376 KB Output is correct
9 Correct 2 ms 376 KB Output is correct
10 Correct 29 ms 4972 KB Output is correct
11 Correct 52 ms 4968 KB Output is correct
12 Correct 22 ms 3688 KB Output is correct
13 Correct 315 ms 40640 KB Output is correct
14 Correct 321 ms 50368 KB Output is correct
15 Correct 306 ms 48320 KB Output is correct
16 Correct 356 ms 49396 KB Output is correct
17 Correct 290 ms 49344 KB Output is correct
18 Correct 296 ms 50212 KB Output is correct
19 Correct 328 ms 50240 KB Output is correct
20 Correct 190 ms 37956 KB Output is correct