Submission #1100947

#	Time	Username	Problem	Language	Result	Execution time	Memory
1100947		akzytr	Stove (JOI18_stove)	C++17	50 / 100	268 ms	262144 KiB

stove

#include <bits/stdc++.h>
using namespace std;
template <typename T> using ve = vector<T>;
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<pair<int, int>> times(N);
	for(int i = 0; i < N; i++) {
		scanf("%d", &times[i].fi);
		times[i].se = 1;
	}
	for(int i = 0; i < N - 1; i++) {
		if(times[i + 1].fi != times[i].fi + 1) {
			times.push_back({times[i].fi + 1, 0});
		}
	}

	times.push_back({times[N - 1].fi + 1, 0});

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

	ve<int> occ(times.size(), 0);
	for(int i = 0; i < times.size(); i++) {
		occ[i] = times[i].se;
	}

	int dp[times.size() + 2][K + 1];

	int mi_left[K + 1] = {};
	int mi_left2[K + 1] = {};

	bool tk = false;

	for(int i = 0; i <= K; i++) {
		mi_left[i] = 0;
		mi_left2[i] = (int)1e9;
	}

	for(int i = times.size() - 1; i >= 0; i--) {
		for(int left = K; left >= 0; left--) {
			tk = (tk || occ[i]);
			dp[i][left] = (!tk ? 0 : (int)1e9);
			mi_left2[left] = min(mi_left2[left], (tk == 0 ? 0 : (int)1e9) + times[i].fi);

			if(left == 0) {
				break;
			}
			if(occ[i]) {
				dp[i][left] = min(dp[i][left], mi_left2[left - 1] - times[i].fi);
				mi_left[left] = dp[i][left];
			} else {
				dp[i][left] = mi_left[left];

				mi_left2[left] = min(mi_left2[left], dp[i][left] + times[i].fi);
			}
		}
	}
	cout << dp[0][K] << 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:31:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int>, std::allocator<std::pair<int, int> > >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   31 |  for(int i = 0; i < times.size(); i++) {
      |                 ~~^~~~~~~~~~~~~~
stove.cpp:17:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   17 |   scanf("%d", &times[i].fi);
      |   ~~~~~^~~~~~~~~~~~~~~~~~~~

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