Submission #102530

#	Time	Username	Problem	Language	Result	Execution time	Memory
102530		Bruteforceman	Cake 3 (JOI19_cake3)	C++11	24 / 100	4080 ms	3852 KiB

cake3

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

pii a[200010];
int n, m;

int opt[200010];

const long long inf = 1e18;

long long query(int i, int j) {
	vector <int> v;
	long long ans = -2 * (a[j].first - a[i].first);
	for(int x = i; x <= j; x++) {
		v.push_back(a[x].second);
	}
	sort(v.begin(), v.end(), greater <int> ());
	for(int i = 0; i < m; i++) {
		ans += v[i];
	}
	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);
	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);
		// cout << change << endl;
		if(change <= n) {
			v.emplace_back(change, i);
		}
	}
	for(int i = m; i <= n; i++) {
		// cout << opt[i] << ' ' << i << endl;
		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:51:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   while(l + 1 < v.size() && v[l + 1].first <= i) {
         ~~~~~~^~~~~~~~~~
cake3.cpp:39:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d %d", &n, &m);
  ~~~~~^~~~~~~~~~~~~~~~~
cake3.cpp:42:8: 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: 0 / 76