Submission #365437

#	Time	Username	Problem	Language	Result	Execution time	Memory
365437		dynam1c	Zalmoxis (BOI18_zalmoxis)	C++17	100 / 100	350 ms	61716 KiB

zalmoxis

//#pragma comment(linker, "/stack:200000000")
//#pragma GCC optimize("Ofast")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
#include <bits/stdc++.h>

using namespace std;
typedef long long ll;

#define endl "\n"
#define all(c) (c).begin(),(c).end()

// if you're reading this i hope to meet you in IOI 2021
// RECHECK CONSTRAINTS AFTER MAKING A REDUCTION

signed main() {
	// freopen("input.txt", "r", stdin); freopen("output.txt", "w", stdout);
	std::ios::sync_with_stdio(false);
	cin.tie(0);
	
	int n, k;
	cin >> n >> k;
	vector<array<int, 3>> arr(n);
	for (int i = 0; i < n; i++)
		cin >> arr[i][0], arr[i][1] = i, arr[i][2] = i+1;
	auto oarr = arr;
	priority_queue<array<int, 2>> aug;
	for (int ii = 0; ii < 30; ii++) {
		vector<array<int, 3>> ar2;
		for (int i = 0; i < arr.size(); i++) {
			if (arr[i][0] == ii) {
				if (i < arr.size()-1 and arr[i+1][0] == ii)
					ar2.push_back({arr[i][0]+1, arr[i][1], arr[i+1][2]}), i++;
				else 
					ar2.push_back({arr[i][0]+1, arr[i][1], arr[i][2]}), aug.push({arr[i][0], arr[i][2]});
			} else ar2.push_back(arr[i]);
		}
		arr = ar2;
	}
	while (aug.size() < k) {
		auto [x, i] = aug.top(); aug.pop();
		aug.push({x-1, i});
		aug.push({x-1, i});
	}
	vector<vector<int>> g(n+1);
	vector<int> res;
	while (!aug.empty()) {
		auto [x, i] = aug.top(); aug.pop();
		g[i].push_back(x);
	}
	arr = oarr;
	for (int i = 0; i <= n; i++) {
		reverse(all(g[i]));
		for (int e : g[i]) res.push_back(e);
		if (i < n) res.push_back(arr[i][0]);
	}
	for (int e : res) cout << e << " ";
	cout << endl;
}
/* --- PSolving ---
 * Simplifying (getting rid of variables, conditions, code logic, etc.)
 * Reframing
 * Solving a subtask (subgoal, aux. problem, removing a condition or fixing a parameter, etc.)
 * Inducing
 * Divide and conquer
 * Working backwards
 * Visual intuition
 * !! Reductions don't have to be specializations, they can be generalizations
 */

Compilation message (stderr)

zalmoxis.cpp: In function 'int main()':
zalmoxis.cpp:29:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::array<int, 3> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   29 |   for (int i = 0; i < arr.size(); i++) {
      |                   ~~^~~~~~~~~~~~
zalmoxis.cpp:31:11: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::array<int, 3> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   31 |     if (i < arr.size()-1 and arr[i+1][0] == ii)
      |         ~~^~~~~~~~~~~~~~
zalmoxis.cpp:39:20: warning: comparison of integer expressions of different signedness: 'std::priority_queue<std::array<int, 2> >::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   39 |  while (aug.size() < k) {
      |         ~~~~~~~~~~~^~~

• Subtask 1: 30 / 30
• Subtask 2: 70 / 70