oj.uz

답안 #496873

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
496873 2021-12-22T05:50:50 Z Ziel XOR Sum (info1cup17_xorsum) C++17
7 / 100
 1600 ms 131076 KB 
/**
 * LES GREATEABLES BRO TEAM
**/

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>

using namespace std;
using namespace __gnu_pbds;

template<class T>
using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
using ll = long long;
#define sz(x) (int)x.size()
const bool FLAG = false;
void setIO(const string &f = "");

void solve() {
    int n;
    cin >> n;
    vector<int> a(n);
    int mx = 0, res = 0;
    for (int &x: a) {
    	cin >> x;
    	mx = max(mx, x);
    }

    if (n * n <= 4e8) {
    	for (int i = 0; i < n; i++) {
    		for (int j = i; j < n; j++) {
    			res ^= (a[i] + a[j]);
    		}
    	}
    } else if (mx * mx <= 4e8) {
    	set<pair<int, int>> s;
    	ordered_set<int> occ[mx + 1];
    	for (int i = 0; i < n; i++) {
    		s.insert({i, a[i]});
    		occ[a[i]].insert(i);
    	}
    	vector<int> v(mx + mx + 2);
    	for (int a = 1; a <= mx; a++) {
    		for (int b = 1; b <= mx; b++) {
    			for (int pos: occ[a]) {
    				int k = sz(occ[b]) - occ[b].order_of_key(pos);
					v[a + b] += k;
    			}
    		}
    	}
    	for (int i = 1; i <= mx + mx; i++)
    		res ^= (v[i] % 2) * i;
    }

	cout << res;
}

signed main() {
    setIO();
    
    int tt = 1;
    if (FLAG) {
    	cin >> tt;
    }
    while (tt--) {
    	solve();
    }
    
    return 0;
}

void setIO(const string &f) {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    if (fopen((f + ".in").c_str(), "r")) {
        freopen((f + ".in").c_str(), "r", stdin);
        freopen((f + ".out").c_str(), "w", stdout);
    }
}

Compilation message

xorsum.cpp: In function 'void setIO(const string&)':
xorsum.cpp:75:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   75 |         freopen((f + ".in").c_str(), "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
xorsum.cpp:76:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   76 |         freopen((f + ".out").c_str(), "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
7.0 / 7.0

# 결과 실행 시간 메모리 Grader output
1 Correct 5 ms 324 KB Output is correct
2 Correct 7 ms 356 KB Output is correct

Subtask #2
0 / 11.0

# 결과 실행 시간 메모리 Grader output
1 Execution timed out 1693 ms 4540 KB Time limit exceeded
2 Halted 0 ms 0 KB -

Subtask #3
0 / 21.0

# 결과 실행 시간 메모리 Grader output
1 Execution timed out 1693 ms 4540 KB Time limit exceeded
2 Halted 0 ms 0 KB -

Subtask #4
0 / 38.0

# 결과 실행 시간 메모리 Grader output
1 Correct 5 ms 324 KB Output is correct
2 Correct 7 ms 356 KB Output is correct
3 Runtime error 61 ms 131076 KB Execution killed with signal 9
4 Halted 0 ms 0 KB -

Subtask #5
0 / 23.0

# 결과 실행 시간 메모리 Grader output
1 Correct 5 ms 324 KB Output is correct
2 Correct 7 ms 356 KB Output is correct
3 Execution timed out 1693 ms 4540 KB Time limit exceeded
4 Halted 0 ms 0 KB -