oj.uz

답안 #1106602

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
1106602 2024-10-30T17:32:12 Z xnqs 구경하기 (JOI13_watching) C++17
50 / 100
 190 ms 1532 KB 
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
#include <utility>
#include <algorithm>
#include <cstring>

int x, p, q;
std::vector<int> arr;
char dp[101][101][101];

char sol(int pos, int a, int b, int cap) {
	if (a>p||b>q) {
		return 0;
	}
	if (pos==x) {
		return 1;
	}
	if (dp[pos][a][b]!=-1) {
		return dp[pos][a][b];
	}
 
	char ret = 0;
	for (int i = pos; i < x; i++) {
		if (arr[i]-arr[pos]+1 <= cap) {
			ret |= sol(i+1,a+1,b,cap);
		}
		if (arr[i]-arr[pos]+1 <= 2*cap) {
			ret |= sol(i+1,a,b+1,cap);
		}
	}
	return dp[pos][a][b] = ret;
}

bool can_solve(int cap, bool debug = 0) {
	if (x<=100) {
		memset(dp,-1,sizeof(dp));
		return sol(0,0,0,cap);
	}
	else {
		std::vector<int> tmp = arr;
		if (debug) {
			for (const auto& i : tmp) {
				std::cout << i << " ";
			}
			std::cout << "\n";
		}
		
		// first use the large cameras
		for (int iterations = 0; iterations < q && !tmp.empty(); iterations++) {
			int w = 2*cap;
			int max = -1, max_l = -1, max_r = -1;
			for (int l = 0, r = 0; r < tmp.size(); r++) {
				while (tmp[r]-tmp[l]+1 > w) {
					++l;
				}
	 
				if (r-l+1>max) {
					max = r-l+1;
					max_l = l;
					max_r = r;
				}
			}
	 
			tmp.erase(tmp.begin()+max_l,tmp.begin()+max_r+1);
			if (debug) {
				std::cout << max_l << " " << max_r << "\n";
				for (const auto& i : tmp) {
					std::cout << i << " ";
				}
				std::cout << "\n";
			}
		}
	 
		// then the small cameras
		for (int iterations = 0; iterations < p && !tmp.empty(); iterations++) {
			int w = cap;
			int max = -1, max_l = -1, max_r = -1;
			for (int l = 0, r = 0; r < tmp.size(); r++) {
				while (tmp[r]-tmp[l]+1 > w) {
					++l;
				}
	 
				if (r-l+1>max) {
					max = r-l+1;
					max_l = l;
					max_r = r;
				}
			}
	 
			tmp.erase(tmp.begin()+max_l,tmp.begin()+max_r+1);
			if (debug) {
				std::cout << max_l << " " << max_r << "\n";
				for (const auto& i : tmp) {
					std::cout << i << " ";
				}
				std::cout << "\n";
			}
		}
		
		return tmp.empty();
	}
}
 
int main() {
	std::ios_base::sync_with_stdio(false);
	std::cin.tie(NULL);
	std::cout.tie(NULL);
 
	std::cin >> x >> p >> q;
 
	// we only need at most x cameras in total, out of which we'll greedily take as many big cameras as possible
	if (p+q>x) {
		q = std::min(q, x);
		p = x-q;
	}
 
	for (int i = 0, tmp; i < x; i++) {
		std::cin >> tmp;
		arr.emplace_back(tmp);
	}
 
	std::sort(arr.begin(),arr.end());
	const auto bs = [&]() {
		int ret = 1000000001;
		int l = 1, r = 1000000000;
		while (l<=r) {
			int m = (l+r)>>1;
			if (can_solve(m)) {
				ret = m;
				r = m-1;
			}
			else {
				l = m+1;
			}
		}
		return ret;
	};
 
	std::cout << bs() << "\n";
	//can_solve(bs(),1);
}

Compilation message

watching.cpp: In function 'bool can_solve(int, bool)':
watching.cpp:54:29: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   54 |    for (int l = 0, r = 0; r < tmp.size(); r++) {
      |                           ~~^~~~~~~~~~~~
watching.cpp:80:29: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   80 |    for (int l = 0, r = 0; r < tmp.size(); r++) {
      |                           ~~^~~~~~~~~~~~

Subtask #1
50.0 / 50.0

# 결과 실행 시간 메모리 Grader output
1 Correct 4 ms 1360 KB Output is correct
2 Correct 2 ms 1360 KB Output is correct
3 Correct 2 ms 1360 KB Output is correct
4 Correct 52 ms 1360 KB Output is correct
5 Correct 7 ms 1360 KB Output is correct
6 Correct 7 ms 1360 KB Output is correct
7 Correct 9 ms 1532 KB Output is correct
8 Correct 16 ms 1360 KB Output is correct
9 Correct 18 ms 1360 KB Output is correct
10 Correct 75 ms 1360 KB Output is correct
11 Correct 85 ms 1360 KB Output is correct
12 Correct 190 ms 1360 KB Output is correct
13 Correct 21 ms 1528 KB Output is correct
14 Correct 23 ms 1360 KB Output is correct
15 Correct 20 ms 1468 KB Output is correct

Subtask #2
0 / 50.0

# 결과 실행 시간 메모리 Grader output
1 Incorrect 1 ms 336 KB Output isn't correct
2 Halted 0 ms 0 KB -