#include <bits/stdc++.h> using namespace std; #define int long long #define FASTIO ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL); #define all(x) (x).begin(), (x).end() #define pb push_back #define pii pair<int, int> #define ff first #define ss second #define PI acos(-1) #define ld long double template <class T> bool ckmin(T& a, const T& b) {return a > b ? a = b, true : false;} template <class T> bool ckmax(T& a, const T& b) {return a < b ? a = b, true : false;} const int mod = 1e9+7, N = 2e5+5; int msb(int val){return sizeof(int)*8-__builtin_clzll(val);} int a[N], n, m, k; void solve(int test_case){ int i, j; cin >> n; int l=0, r=n; while(l+1 < r){ int mid = (l+r)/2; if(mid < mod && mid*(mid+1)/2 < n){ l = mid; }else r = mid; } int lst = l*(l+1)/2; int start = lst*2-l+1; start += (n-lst-1)*2; cout << start << '\n'; return; } signed main(){ FASTIO; #define MULTITEST 0 #if MULTITEST int _T; cin >> _T; for(int T_CASE = 1; T_CASE <= _T; T_CASE++) solve(T_CASE); #else solve(1); #endif return 0; }

oddeven.cpp: In function 'void solve(long long int)':
oddeven.cpp:19:6: warning: unused variable 'i' [-Wunused-variable]
   19 |  int i, j;
      |      ^
oddeven.cpp:19:9: warning: unused variable 'j' [-Wunused-variable]
   19 |  int i, j;
      |         ^