# | Time | Username | Problem | Language | Result | Execution time | Memory |
---|---|---|---|---|---|---|---|
859966 | aykhn | Odd-even (IZhO11_oddeven) | C++14 | 0 ms | 0 KiB |
This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include <bits/stdc++.h>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/assoc_container.hpp>
// author : aykhn
using namespace std;
using namespace __gnu_pbds;
typedef long long ll;
#define pb push_back
#define ins insert
#define mpr make_pair
#define all(v) v.begin(), v.end()
#define bpc __builtin_popcount
#define pii pair<int, int>
#define pll pair<ll, ll>
#define fi first
#define se second
#define int ll
#define infll 0x3F3F3F3F3F3F3F3F
#define inf 0x3F3F3F3F
template<class T> using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
__int128 read() {
__int128 x = 0, f = 1;
char ch = getchar();
while (ch < '0' || ch > '9') {
if (ch == '-') f = -1;
ch = getchar();
}
while (ch >= '0' && ch <= '9') {
x = x * 10 + ch - '0';
ch = getchar();
}
return x * f;
}
void print(__int128 x) {
if (x < 0) {
putchar('-');
x = -x;
}
if (x > 9) print(x / 10);
putchar(x % 10 + '0');
}
signed main()
{
ios_base::sync_with_stdio(0);
cin.tie(nullptr);
__int128 n;
n = read();
__int128 l = 1;
__int128 r = 1e9;
int INF = 2e18;
while (l < r)
{
__int128 mid = (l + r) >> 1;
if ((mid + 1) >= (INF + mid - 1)/mid || mid * (mid + 1) / 2 >= n) r = mid;
else l = mid + 1;
}
__int128 x = l - 1;
__int128 y = n - 1;
print((y - x) * 2 + x + 1) << '\n';
}