Submission #102532

#	Time	Username	Problem	Language	Result	Execution time	Memory
102532		Bruteforceman	Cake 3 (JOI19_cake3)	C++11	100 / 100	2341 ms	209516 KiB

cake3

#include "bits/stdc++.h"
using namespace std;
typedef pair <int, int> pii;

pii a[200010];
int opt[200010];
const long long inf = 1e18;
long long rev[200010];
int cmp[200010];

struct node {
	node *l, *r;
	int cnt;
	long long sum;
	node () {
		l = r = NULL;
		cnt = 0;
		sum = 0;
	}
	void merge() {
		cnt = 0;
		sum = 0;
		if(l) {
			cnt += l -> cnt;
			sum += l -> sum;
		}
		if(r) {
			cnt += r -> cnt;
			sum += r -> sum;
		}
	}
} *t[200010];
typedef node* pnode;
int idx;

void insert(pnode &prev, pnode &cur, int val, int b = 1, int e = idx) {
	cur = new node();
	if(b == e) {
		cur -> cnt = prev -> cnt + 1;
		cur -> sum = prev -> sum + rev[b];
		return ;
	}
	int m = (b + e) >> 1;
	if(val <= m) {
		cur -> r = prev -> r;
		insert(prev -> l, cur -> l, val, b, m);
	} else {
		cur -> l = prev -> l;
		insert(prev -> r, cur -> r, val, m + 1, e);
	}
	cur -> merge();
}

typedef pair <int, long long> data;

long long Query(pnode prev, pnode cur, int k, int b = 1, int e = idx) {
	if(b == e) {
		return 1LL * rev[b] * k;
	}
	int m = (b + e) >> 1;
	int rt = (cur -> r -> cnt) - (prev -> r -> cnt);
	if(rt >= k) {
		return Query(prev -> r, cur -> r, k, m + 1, e);
	} else {
		return (cur -> r -> sum) - (prev -> r -> sum) + Query(prev -> l, cur -> l, k - rt, b, m);
	}
}

void build(pnode &cur, int b = 1, int e = idx) {
	cur = new node();
	if(b == e) {
		return ;
	}
	int m = (b + e) >> 1;
	build(cur -> l, b, m);
	build(cur -> r, m + 1, e);
}

int n, m;

long long query(int i, int j) {
	vector <int> v;
	long long ans = -2 * (a[j].first - a[i].first);
	ans += Query(t[i - 1], t[j], m);
	return ans;
}

int search(int b, int e, int p, int q) {
	if(b > e) return n+1;
	if(b == e) {
		return query(p, b) <= query(q, b) ? b : n+1;
	}
	int mid = (b + e) >> 1;
	if(query(p, mid) <= query(q, mid)) {
		return search(b, mid, p, q);
	} else {
		return search(mid + 1, e, p, q);
	}
}
int main(int argc, char const *argv[])
{
	scanf("%d %d", &n, &m);
	for(int i = 1; i <= n; i++) {
		int p, q;
		scanf("%d %d", &p, &q);
		a[i] = pii(q, p);
	}
	sort(a + 1, a + n + 1);

	map <int, int> mp;
	for(int i = 1; i <= n; i++) {
		mp[a[i].second];
	}
	for(auto &i : mp) {
		i.second = ++idx;
		rev[idx] = i.first;
	}
	for(int i = 0; i <= n; i++) {
		t[i] = NULL;
	}
	build(t[0]);
	for(int i = 1; i <= n; i++) {
		insert(t[i - 1], t[i], mp[a[i].second]);
	}

	long long ans = LLONG_MIN;
	vector <pii> v;
	v.emplace_back(m, 1);
	int l = 0;
	for(int i = 2; i <= n; i++) {
		while(l + 1 < v.size() && v[l + 1].first <= i) {
			++l;
		}
		opt[i] = v[l].second;
		while(!v.empty() && i + m - 1 <= v.back().first && query(i, v.back().first) >= query(v.back().second, v.back().first)) {
			v.pop_back();
		} 
		int change = search(max(i + m - 1, v.back().first), n, v.back().second, i);
		if(change <= n) {
			v.emplace_back(change, i);
		}
	}
	for(int i = m; i <= n; i++) {
		ans = max(ans, query(opt[i], i));
	}
	printf("%lld\n", ans);
	return 0;
}

Compilation message (stderr)

cake3.cpp: In function 'int main(int, const char**)':
cake3.cpp:131:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   while(l + 1 < v.size() && v[l + 1].first <= i) {
         ~~~~~~^~~~~~~~~~
cake3.cpp:102:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d %d", &n, &m);
  ~~~~~^~~~~~~~~~~~~~~~~
cake3.cpp:105:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d %d", &p, &q);
   ~~~~~^~~~~~~~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 19 / 19
• Subtask 3: 76 / 76