Submission #1076432

#	Time	Username	Problem	Language	Result	Execution time	Memory
1076432		MilosMilutinovic	Lasers (NOI19_lasers)	C++14	100 / 100	204 ms	28464 KiB

lasers

#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <algorithm>
#include <cmath>
#include <vector>
#include <set>
#include <map>
#include <unordered_set>
#include <unordered_map>
#include <queue>
#include <ctime>
#include <cassert>
#include <complex>
#include <string>
#include <cstring>
#include <chrono>
#include <random>
#include <bitset>
#include <array>
using namespace std;
 
#ifdef LOCAL
	#define eprintf(...) {fprintf(stderr, __VA_ARGS__);fflush(stderr);}
#else
	#define eprintf(...) 42
#endif
 
using ll = long long;
using ld = long double;
using uint = unsigned int;
using ull = unsigned long long;
template<typename T>
using pair2 = pair<T, T>;
using pii = pair<int, int>;
using pli = pair<ll, int>;
using pll = pair<ll, ll>;
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
ll myRand(ll B) {
	return (ull)rng() % B;
}
 
#define pb push_back
#define mp make_pair
#define all(x) (x).begin(),(x).end()
#define fi first
#define se second
 
clock_t startTime;
double getCurrentTime() {
	return (double)(clock() - startTime) / CLOCKS_PER_SEC;
}

int l, r;
vector<pii> segs;
vector<pii> mySegs;
void addSeg(int segL, int segR) {
	if(segL > segR)
		return;
	mySegs.emplace_back(segL, segR);
}

int main()
{
	startTime = clock();
//	freopen("input.txt", "r", stdin);
//	freopen("output.txt", "w", stdout);

	scanf("%d%d", &l, &r);
	for (int i = 0; i < r; i++) {
		int x;
		scanf("%d", &x);
		vector<int> a(x);
		for (int j = 0; j < x; j++)
			scanf("%d", &a[j]);
		int sL = 0;
		int sR = accumulate(a.begin(), a.end(), 0);
		mySegs.clear();
		addSeg(1, l - sR);
		for (int j = 0; j < x; j++) {
			sL += a[j];
			sR -= a[j];
			addSeg(sL + 1, l - sR);
		}
		vector<pii> events;
		for (int j = 0; j < mySegs.size(); j++) {
			events.emplace_back(mySegs[j].first, -1);
			events.emplace_back(mySegs[j].second, 1);
		}
		int bal = 0, stS = -1;
		sort(events.begin(), events.end());
		for (int j = 0; j < events.size(); j++) {
			if(events[j].second == -1) {
				if(bal == 0)
					stS = events[j].first;
				bal++;
			} else {
				bal--;
				if(bal == 0) {
					segs.emplace_back(stS, events[j].first);
				}
			}
		}
	}
	vector<pii> events;
	for (int i = 0; i < segs.size(); i++) {
		events.emplace_back(segs[i].first, -1);
		events.emplace_back(segs[i].second, 1);
	}
	sort(events.begin(), events.end());
	int bal = 0, ans = 0, stS = 0;
	for (int i = 0; i < events.size(); i++) {
		if(events[i].second == -1) {
			bal++;
			if(bal == r)
				stS = events[i].first;
		} else {
			if(bal == r)
				ans += events[i].first - stS + 1;
			bal--;
		}
	}
	printf("%d\n", l - ans);
}

Compilation message (stderr)

lasers.cpp: In function 'int main()':
lasers.cpp:86:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   86 |   for (int j = 0; j < mySegs.size(); j++) {
      |                   ~~^~~~~~~~~~~~~~~
lasers.cpp:92:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   92 |   for (int j = 0; j < events.size(); j++) {
      |                   ~~^~~~~~~~~~~~~~~
lasers.cpp:106:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  106 |  for (int i = 0; i < segs.size(); i++) {
      |                  ~~^~~~~~~~~~~~~
lasers.cpp:112:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  112 |  for (int i = 0; i < events.size(); i++) {
      |                  ~~^~~~~~~~~~~~~~~
lasers.cpp:69:7: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   69 |  scanf("%d%d", &l, &r);
      |  ~~~~~^~~~~~~~~~~~~~~~
lasers.cpp:72:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   72 |   scanf("%d", &x);
      |   ~~~~~^~~~~~~~~~
lasers.cpp:75:9: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   75 |    scanf("%d", &a[j]);
      |    ~~~~~^~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 14 / 14
• Subtask 3: 20 / 20
• Subtask 4: 21 / 21
• Subtask 5: 22 / 22
• Subtask 6: 13 / 13