Submission #170699

#	Time	Username	Problem	Language	Result	Execution time	Memory
170699		Lightning	Odd-even (IZhO11_oddeven)	C++14	0 / 100	2 ms	504 KiB

oddeven

#include <iostream>
#include <algorithm>
#include <vector>
#include <cmath>
#include <set>
#include <map>
#include <iomanip>
#include <stack>
#include <queue>
#include <deque>

using namespace std;

typedef long long ll;
typedef pair <int, int> pii;

#define sz(a) (int)a.size()
#define all(a) a.begin(), a.end()
#define pb push_back
#define ppb pop_back
#define mkp make_pair
#define F first
#define S second
#define show(a) cerr << #a <<" -> "<< a <<"\n"
#define fo(a, b, c, d) for(int (a) = (b); (a) <= (c); (a) += (d))
#define foo(a, b, c ,d) for(int (a) = (b); (a) >= (c); (a) -= (d))
#define int ll

const int N = 2e5 + 5;
const int INF = 1e9 + 5;

int n;

int sum(int x) {
	return (x * (x + 1)) / 2;
}

main () {
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	cin >> n;
	int l = 1, r = n;
	while(l < r) {
		int mid = (l + r) / 2;
		if(sum(mid) >= n) r = mid;
		else l = mid + 1;
	}
	int num = r;
	int fir = (num * (num - 2)) + 2;
	int pos = n - sum(num - 1);
	cout << fir + (2 * (pos - 1));
	return 0;
}
/*
	If you only do what you can do, 
	You will never be more than you are now!

	We must all suffer from one of two pains: the pain of discipline or the pain of regret. 
	The difference is discipline weighs grams while regret weighs tons.
*/

Compilation message (stderr)

oddeven.cpp:38:7: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
 main () {
       ^

• Subtask 1: 0 / 100