Submission #35526

#	Time	Username	Problem	Language	Result	Execution time	Memory
35526		sinhriv	medians (balkan11_medians)	C++14	5 / 100	189 ms	15056 KiB

medians

#include <bits/stdc++.h>

using namespace std;

const int N = 200010;

int n;
int a[N];
int b[N];
vector < pair < int, int > > relate;


int d(int x){
	if(x < 0) return abs(x);
	return n + n - x;
}

int getopp(int x){
	return x / abs(x);
}

bool cmp(pair < int, int > x, pair < int, int > y){
	if(getopp(x.first) != getopp(y.first)){
		return getopp(x.first) < getopp(y.first);
	}
	return d(x.first) < d(y.first);
}

set < int > unused;

void solve(int x, int p){
	if(x < 0){
		x = abs(x);
		auto it = unused.upper_bound(x);
		if(it == unused.begin()) relate.emplace_back(-x, p);
		else {
			a[p] = *(--it);
			unused.erase(a[p]);
		}
	}
	else{
		auto it = unused.lower_bound(x);
		if(it == unused.end()) relate.emplace_back(x, p);
		else{
			a[p] = *it;
			unused.erase(it);
		}
	}
}

int main(){
	if(fopen("1.inp", "r")){
		freopen("1.inp", "r", stdin);
	}

	set < int > used;

	scanf("%d", &n);
	for(int i = 1; i <= n; ++i){
		scanf("%d", b + i);
		used.insert(b[i]);
		if(i != 1) unused.insert(b[i]);
	}

	a[1] = b[1];
	unused.erase(a[1]);


	for(int i = 2; i <= n; ++i){
		if(b[i] == b[i - 1]){
			solve(b[i], i + i - 1);
			solve(-b[i], i + i - 2);
			continue;
		}
		if(b[i] < b[i - 1]){
			if(unused.count(b[i])){
				a[i + i - 1] = b[i];
				unused.erase(b[i]);
			}
			else solve(-b[i], i + i - 1);
				
			solve(-b[i], i + i - 2);
		}
		else{
			if(unused.count(b[i])){
				a[i + i - 1] = b[i];
				unused.erase(b[i]);
			}
			else solve(b[i], i + i - 1);
			solve(b[i], i + i - 2);
		}
	}

	set < int > fre;
	for(int i = 1; i < n + n; ++i){
		if(used.count(i) == 0) fre.insert(i);
	}

	sort(relate.begin(), relate.end(), cmp);
	for(auto p : relate){
		if(p.first < 0){
			a[p.second] = *fre.begin();
			fre.erase(fre.begin());
		}
		else{
			a[p.second] = *fre.rbegin();
			fre.erase(a[p.second]);
		}
	}

	for(int i = 1; i < n + n; ++i){
		assert(a[i] != 0);
		printf("%d ", a[i]);
	}

	return 0;
}

Compilation message (stderr)

medians.cpp: In function 'int main()':
medians.cpp:53:31: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   freopen("1.inp", "r", stdin);
                               ^
medians.cpp:58:17: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &n);
                 ^
medians.cpp:60:21: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d", b + i);
                     ^

• Subtask 1: 5 / 65
• Subtask 2: 0 / 35