#pragma GCC optimize("O3") #pragma GCC optimize("Ofast") #pragma GCC optimize("inline") #pragma GCC optimize("-fgcse") #pragma GCC optimize("-fgcse-lm") #pragma GCC optimize("-fipa-sra") #pragma GCC optimize("-ftree-pre") #pragma GCC optimize("-ftree-vrp") #pragma GCC optimize("-fpeephole2") #pragma GCC optimize("-ffast-math") #pragma GCC optimize("-fsched-spec") #pragma GCC optimize("unroll-loops") #pragma GCC optimize("-falign-jumps") #pragma GCC optimize("-falign-loops") #pragma GCC optimize("-falign-labels") #pragma GCC optimize("-fdevirtualize") #pragma GCC optimize("-fcaller-saves") #pragma GCC optimize("-fcrossjumping") #pragma GCC optimize("-fthread-jumps") #pragma GCC optimize("-funroll-loops") #pragma GCC optimize("-fwhole-program") #pragma GCC optimize("-freorder-blocks") #pragma GCC optimize("-fschedule-insns") #pragma GCC optimize("inline-functions") #pragma GCC optimize("-ftree-tail-merge") #pragma GCC optimize("-fschedule-insns2") #pragma GCC optimize("-fstrict-aliasing") #pragma GCC optimize("-fstrict-overflow") #pragma GCC optimize("-falign-functions") #pragma GCC optimize("-fcse-skip-blocks") #pragma GCC optimize("-fcse-follow-jumps") #pragma GCC optimize("-fsched-interblock") #pragma GCC optimize("-fpartial-inlining") #pragma GCC optimize("no-stack-protector") #pragma GCC optimize("-freorder-functions") #pragma GCC optimize("-findirect-inlining") #pragma GCC optimize("-fhoist-adjacent-loads") #pragma GCC optimize("-frerun-cse-after-loop") #pragma GCC optimize("inline-small-functions") #pragma GCC optimize("-finline-small-functions") #pragma GCC optimize("-ftree-switch-conversion") #pragma GCC optimize("-foptimize-sibling-calls") #pragma GCC optimize("-fexpensive-optimizations") #pragma GCC optimize("-funsafe-loop-optimizations") #pragma GCC optimize("inline-functions-called-once") #pragma GCC optimize("-fdelete-null-pointer-checks") #include <bits/stdc++.h> #define GOOD_LUCK ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0); #define int long long #define endl "\n" #define ff first #define ss second #define pb push_back #define all(v) v.begin(), v.end() using namespace std; constexpr int MAX = 2e+5 + 1, INF = 2e+9, MOD = 1e+9 + 7, K = 29; void _() { int n; cin >> n; vector <int> v(n); for (int &i : v) cin >> i; int res=0; for (int i = K; i >= 0; i--) { vector <int> x = v; int m = (1LL << (i + 1)); for (int &j : x) j %= m; sort(all(x)); int c=0; while (!x.empty()) { int k = x.back(); int mn = (1LL << i); int mx = (1LL << (i + 1)) - 1; mn -= k, mx -= k; if (mn <= mx) c += upper_bound(all(x), mx) - lower_bound(all(x), mn); mn = (1LL << i) * 3; mx = (1LL << (i + 2)) - 1; mn -= k, mx -= k; if (mn <= mx) c += upper_bound(all(x), mx) - lower_bound(all(x), mn); x.pop_back(); } res += (1LL << i) * (c % 2); } cout << res; } signed main() { GOOD_LUCK int tests=1; // cin >> tests; for (int i=1; i <= tests; i++) { _(); cout << endl; } return 0; } /* 0011 0110 0110 1001 001 011 110 110 100 -> min 111 -> max */

xorsum.cpp:21:39: warning: bad option '-fwhole-program' to pragma 'optimize' [-Wpragmas]
   21 | #pragma GCC optimize("-fwhole-program")
      |                                       ^
xorsum.cpp:28:41: warning: bad option '-fstrict-overflow' to pragma 'optimize' [-Wpragmas]
   28 | #pragma GCC optimize("-fstrict-overflow")
      |                                         ^
xorsum.cpp:30:41: warning: bad option '-fcse-skip-blocks' to pragma 'optimize' [-Wpragmas]
   30 | #pragma GCC optimize("-fcse-skip-blocks")
      |                                         ^
xorsum.cpp:44:51: warning: bad option '-funsafe-loop-optimizations' to pragma 'optimize' [-Wpragmas]
   44 | #pragma GCC optimize("-funsafe-loop-optimizations")
      |                                                   ^
xorsum.cpp:59:8: warning: bad option '-fwhole-program' to attribute 'optimize' [-Wattributes]
   59 | void _() {
      |        ^
xorsum.cpp:59:8: warning: bad option '-fstrict-overflow' to attribute 'optimize' [-Wattributes]
xorsum.cpp:59:8: warning: bad option '-fcse-skip-blocks' to attribute 'optimize' [-Wattributes]
xorsum.cpp:59:8: warning: bad option '-funsafe-loop-optimizations' to attribute 'optimize' [-Wattributes]
xorsum.cpp:88:13: warning: bad option '-fwhole-program' to attribute 'optimize' [-Wattributes]
   88 | signed main() {
      |             ^
xorsum.cpp:88:13: warning: bad option '-fstrict-overflow' to attribute 'optimize' [-Wattributes]
xorsum.cpp:88:13: warning: bad option '-fcse-skip-blocks' to attribute 'optimize' [-Wattributes]
xorsum.cpp:88:13: warning: bad option '-funsafe-loop-optimizations' to attribute 'optimize' [-Wattributes]