Submission #1100928

#	Time	Username	Problem	Language	Result	Execution time	Memory
1100928		akzytr	Stove (JOI18_stove)	C++17	20 / 100	228 ms	262144 KiB

stove

#include <bits/stdc++.h>
using namespace std;
template <typename T> using ve = vector<T>;
template <typename T, int sz> using ar = array<T, sz>;
typedef long long ll;
#define pb push_back
#define fi first
#define se second
#define endl '\n'

int main() {

	int N, K;
	cin >> N >> K;

	ve<int> times;
	map<int, int> occ;
	for(int i = 0; i < N; i++) {
		int x;
		cin >> x;
		times.pb(x);
		occ[x] = 1;
		times.pb(x + 1);
	}

	sort(times.begin(), times.end());
	times.erase(unique(times.begin(), times.end()), times.end());

	int dp[times.size() + 2][times.size() + 2][2];
	for(int i = 0; i < times.size(); i++) {
		for(int j = 0; j <= K; j++) {
			dp[i][j][0] = (int)1e9;
			dp[i][j][1] = (int)1e9;
		}
	}

	for(int i = times.size() - 1; i >= 0; i--) {
		if(occ[times[i]]) {
			break;
		}
		for(int k = 0; k <= K; k++) {
			dp[i][k][0] = 0;
		}
	}

	for(int i = times.size() - 1; i >= 0; i--) {
		for(int left = K; left >= 1; left--) {
			// ON
			if(occ[times[i]]) {
				for(int j = i + 1; j < times.size(); j++) {
					dp[i][left][1] = min(dp[i][left][1], dp[j][left - 1][0] + times[j] - times[i]);
				}
			} else {
				for(int j = i + 1; j < times.size(); j++) {
					if(occ[times[j]] == 1) {
						dp[i][left][0] = min(dp[i][left][0], dp[j][left][1]);
						break;
					}
				}
			}
		}
	}

	cout << min(dp[0][K][0], dp[0][K][1]) << endl;
}

/*
Subtask 1) N<=20 & Ti<=20

N * K * T greedy


DP[i][left][on] which means the stove is on on the i'th day

DP[i][left][off]
*/

Compilation message (stderr)

stove.cpp: In function 'int main()':
stove.cpp:30:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   30 |  for(int i = 0; i < times.size(); i++) {
      |                 ~~^~~~~~~~~~~~~~
stove.cpp:50:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   50 |     for(int j = i + 1; j < times.size(); j++) {
      |                        ~~^~~~~~~~~~~~~~
stove.cpp:54:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   54 |     for(int j = i + 1; j < times.size(); j++) {
      |                        ~~^~~~~~~~~~~~~~

• Subtask 1: 20 / 20
• Subtask 2: 0 / 30
• Subtask 3: 0 / 50