Submission #591131

#	Time	Username	Problem	Language	Result	Execution time	Memory
591131		GusterGoose27	The short shank; Redemption (BOI21_prison)	C++11	80 / 100	2017 ms	66888 KiB

prison

#pragma GCC optimize("Ofast")
#pragma GCC target("avx2")

#include <bits/stdc++.h>

using namespace std;

typedef long double ld;
typedef pair<ld, int> pdi;
typedef pair<int, int> pii;

const int MAXN = 2e6;
pdi dp[MAXN];
const int inf = 1e9;
int n, d, t;
int vals[MAXN];

class STree {
public:
	int n;
	pdi *mn;
	int *lz;
	int *lval;
	int *rval;
	STree() {}
	STree(int nn) {
		n = pow(2, ceil(log2(nn)));
		mn = new pdi[2*n];
		lz = new int[2*n];
		lval = new int[2*n];
		rval = new int[2*n];
		for (int i = 1; i < 2*n; i++) mn[i] = pdi(inf, 0);
		fill(lz, lz+2*n, 0);
		for (int i = n; i < 2*n; i++) {
			lval[i] = i-n;
			rval[i] = i-n+1;
		}
		for (int i = n-1; i > 0; i--) {
			lval[i] = lval[2*i];
			rval[i] = rval[2*i+1];
		}
	}
	void clean() {
		for (int i = 1; i < 2*n; i++) mn[i] = pdi(inf, 0);
		fill(lz, lz+2*n, 0);
	}
	void increment(int l, int r, int v, int cur = 1) {
		if (lval[cur] >= r || rval[cur] <= l) return;
		if (lval[cur] >= l && rval[cur] <= r) {
			lz[cur] += v;
			mn[cur].first += v;
			return;
		}
		increment(l, r, v, 2*cur);
		increment(l, r, v, 2*cur+1);
		mn[cur] = min(mn[2*cur], mn[2*cur+1]);
		mn[cur].first += lz[cur];
	}
	pdi mnval(int l, int r, int cur = 1, int laz = 0) {
		if (lval[cur] >= r || rval[cur] <= l) return pdi(inf, 0);
		if (lval[cur] >= l && rval[cur] <= r) return pdi(mn[cur].first+laz, mn[cur].second);
		laz += lz[cur];
		return min(mnval(l, r, 2*cur, laz), mnval(l, r, 2*cur+1, laz));
	}
	void update(int i, pdi v, int cur = 1, int laz = 0) {
		if (lval[cur] > i || rval[cur] <= i) return;
		if (cur >= n) {
			mn[cur] = pdi(v.first-laz, v.second);
			return;
		}
		laz += lz[cur];
		update(i, v, 2*cur, laz);
		update(i, v, 2*cur+1, laz);
		mn[cur] = min(mn[2*cur], mn[2*cur+1]);
		mn[cur].first += lz[cur];
	}
};

STree s;

const int iters = 25;
//const ld prec = 3e-2;

int get_int(int i) {
	if (vals[i] > t) return i;
	return i+(t-vals[i])+1;
}

bool make_iter(ld &mn, ld &mx, bool force = 0) {
	vector<int> uncolored;
	//STree s(n);
	ld cost = (mn+mx)/2;
	for (int i = n-1; i >= 0; i--) {
		if (i == n-1) dp[i] = pdi(0, 0);
		else {
			pdi mnval = s.mnval(i+1, n);
			mnval.first += cost;
			mnval.second++;
			dp[i] = mnval;
		}
		// if (dp[i].second > d) {
		// 	mn = cost;
		// 	return 0;
		// }
		if (d == 1 && dp[i].second > d) s.update(i, pdi(inf, 0));
		else s.update(i, dp[i]);
		uncolored.push_back(i);
		int r = get_int(i);
		int pos = uncolored.size()-1;
		while (pos >= 0 && uncolored[pos] < r) pos--;
		pos++;
		int prev = n;
		int mult = uncolored.size()-pos;
		for (int i = pos; i < uncolored.size(); i++) {
			s.increment(uncolored[i], prev, mult);
			prev = uncolored[i];
			mult--;
		}
		int num = uncolored.size()-pos;
		for (int i = 0; i < num; i++) uncolored.pop_back();
	}
	pdi overall = s.mnval(0, n);
	if (overall.second == d || force) { // we are done
		cout << round(overall.first-cost*d) << "\n";
		return 1;
	}
	if (overall.second < d) mx = cost;
	else mn = cost;
	return 0;
}

void spec() {
	vector<int> uncolored;
	//STree s(n);
	//ld cost = (mn+mx)/2;
	for (int i = n-1; i >= 0; i--) {
		if (i == n-1) dp[i] = pdi(0, 0);
		else {
			pdi mnval = s.mnval(n-1, n);
			//mnval.first += cost;
			mnval.second++;
			dp[i] = mnval;
		}
		// if (dp[i].second > d) {
		// 	mn = cost;
		// 	return 0;
		// }
		if (d == 1 && dp[i].second > d) s.update(i, pdi(inf, 0));
		else s.update(i, dp[i]);
		uncolored.push_back(i);
		int r = get_int(i);
		int pos = uncolored.size()-1;
		while (pos >= 0 && uncolored[pos] < r) pos--;
		pos++;
		int prev = n;
		int mult = uncolored.size()-pos;
		for (int i = pos; i < uncolored.size(); i++) {
			s.increment(uncolored[i], prev, mult);
			prev = uncolored[i];
			mult--;
		}
		int num = uncolored.size()-pos;
		for (int i = 0; i < num; i++) uncolored.pop_back();
	}
	pdi overall = s.mnval(0, n-1);
	cout << round(overall.first) << "\n";
	return;
	// if (overall.second == d || force) { // we are done
	// 	cout << round(overall.first-cost*d) << "\n";
	// 	//return 1;
	// }
	// if (overall.second < d) mx = cost;
	// else mn = cost;
	// return 0;
}

int main() {
	ios_base::sync_with_stdio(false); cin.tie(NULL);
	cin >> n >> d >> t;
	for (int i = 0; i < n; i++) cin >> vals[i];
	ld mn = 0;
	ld mx = ((ld)n)/d+1;
	s = STree(n);
	if (d == 1) {
		spec();
		return 0;
	}
	for (int t = 0; t < iters; t++) {
	//while (mx-mn > prec) {
		bool fin = make_iter(mn, mx);
		if (fin) return 0;
		s.clean();
	}
	//assert(false);
	make_iter(mn, mx, 1);
}

Compilation message (stderr)

prison.cpp: In function 'bool make_iter(ld&, ld&, bool)':
prison.cpp:114:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  114 |   for (int i = pos; i < uncolored.size(); i++) {
      |                     ~~^~~~~~~~~~~~~~~~~~
prison.cpp: In function 'void spec()':
prison.cpp:157:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  157 |   for (int i = pos; i < uncolored.size(); i++) {
      |                     ~~^~~~~~~~~~~~~~~~~~

• Subtask 1: 15 / 15
• Subtask 2: 10 / 10
• Subtask 3: 20 / 20
• Subtask 4: 10 / 10
• Subtask 5: 25 / 25
• Subtask 6: 0 / 20