Submission #259506

#	Time	Username	Problem	Language	Result	Execution time	Memory
259506		ChrisT	Examination (JOI19_examination)	C++17	0 / 100	320 ms	41820 KiB

examination

#include <bits/stdc++.h>
using namespace std;
const int MN = 2e5 + 5;
int ans[MN], bit[MN];
vector<int> xs;
void getx (int &x) {x = lower_bound(xs.begin(),xs.end(),x) - xs.begin() + 1;}
void inc (int i) {
	for (i=MN-i;i<MN;i+=i&-i) ++bit[i];
}
void dec (int i) {
	for (i=MN-i;i<MN;i+=i&-i) --bit[i];
}
int query (int i) {
	int ret = 0;
	for (i=MN-i;i;i^=i&-i) ret += bit[i];
	return ret;
}
struct Event {
	int x,y,z,id;
};
void cdq (int l, int r, vector<Event> &events) { //over z
	if (events.empty()) return;
	vector<Event> lq,rq;
	int mid = (l + r) / 2;
	for (Event &e : events) {
		if (e.z > mid) {
			rq.push_back(e);
			if (e.id<0) inc(e.y);
		} else {
			lq.push_back(e);
			if (e.id>0) ans[e.id] += query(e.y);
		}
	}
	for (Event &e : rq) if (e.id<0) dec(e.y);
	if (l < r) {
		cdq(l,mid,lq);
		cdq(mid+1,r,rq);
	}
}
int main () {
	int n,q;
	scanf ("%d %d",&n,&q);
	vector<Event> events;
	for (int i = 1; i <= n; i++) {
		int s,t;
		scanf ("%d %d",&s,&t); xs.push_back(t);
		events.push_back({s,t,s+t,-i});
	}
	for (int i = 1; i <= q; i++) {
		int x,y,z;
		scanf ("%d %d %d",&x,&y,&z); xs.push_back(y);
		events.push_back({x,y,z,i});
	}
	sort(xs.begin(),xs.end()); xs.erase(unique(xs.begin(),xs.end()),xs.end());
	for (auto &au : events) getx(au.y);
	xs.clear();
	for (auto &au : events) xs.push_back(au.z);
	sort(xs.begin(),xs.end()); xs.erase(unique(xs.begin(),xs.end()),xs.end());
	for (auto &au : events) getx(au.z);
	sort(events.begin(),events.end(),[](const Event &a, const Event &b) {return a.x > b.x || (a.x == b.x && a.id < b.id);});
	cdq(1,xs.size(),events);
	for (int i = 1; i <= q; i++) printf ("%d\n",ans[i]);
	return 0;
}

Compilation message (stderr)

examination.cpp: In function 'int main()':
examination.cpp:42:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf ("%d %d",&n,&q);
  ~~~~~~^~~~~~~~~~~~~~~
examination.cpp:46:9: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf ("%d %d",&s,&t); xs.push_back(t);
   ~~~~~~^~~~~~~~~~~~~~~
examination.cpp:51:9: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf ("%d %d %d",&x,&y,&z); xs.push_back(y);
   ~~~~~~^~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 2
• Subtask 2: 0 / 20
• Subtask 3: 0 / 21
• Subtask 4: 0 / 57