Submission #66752922

Source Code Expand

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
/**
 * テンプレート出典：http://qiita.com/sorachandu/items/041169d34b9f9b99bcf7
 */
#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
struct Init { Init() { ios::sync_with_stdio(0); cin.tie(0); cout << setprecision(13); } }init;
using ll = long long;
using ld = long double;
using ull = unsigned long long;
using pii = pair<int,int>;
using pll = pair<ll,ll>;
using vi = vector<int>;
using vl = vector<ll>;
using vvi = vector<vector<int>>;
using vvl = vector<vector<ll>>;
using vb = vector<bool>;
using vvb = vector<vector<bool>>;
 
 
הההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההה
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

/**
 * テンプレート出典：http://qiita.com/sorachandu/items/041169d34b9f9b99bcf7
 */
#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
struct Init { Init() { ios::sync_with_stdio(0); cin.tie(0); cout << setprecision(13); } }init;

using ll = long long;
using ld = long double;
using ull = unsigned long long;
using pii = pair<int,int>;
using pll = pair<ll,ll>;
using vi = vector<int>;
using vl = vector<ll>;
using vvi = vector<vector<int>>;
using vvl = vector<vector<ll>>;
using vb = vector<bool>;
using vvb = vector<vector<bool>>;

#define rep(i, x, limit) for (int i = (int)x; i < (int)limit; i++)
#define REP(i, x, limit) for (int i = (int)x; i <= (int)limit; i++)
#define repl(i, x, limit) for (ll i = (ll)x; i < (ll)limit; i++)
#define REPL(i, x, limit) for (ll i = (ll)x; i <= (ll)limit; i++)
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define el '\n'
#define spa " "
#define Yes cout << "Yes" << el
#define No cout << "No" << el
#define YES cout << "YES" << el
#define NO cout << "NO" << el
#define eps (1e-10)
#define Equals(a,b) (fabs((a) - (b)) < eps )
#define debug(x) cerr << #x << " = " << x << el

const double pi = 3.141592653589793238;
const int inf = 1073741823;
const ll infl = 1LL << 60;
const string ABC = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
const string abc = "abcdefghijklmnopqrstuvwxyz";

//std::pairをstd::coutに渡すために"<<"処理を書き換えた物
template<typename T1, typename T2>
std::ostream &operator<< (std::ostream &os, std::pair<T1,T2> p){
    os << "{" << p.first << "," << p.second << "}";
    return os;
}

template<typename T1, typename T2> inline bool chmax(T1 &a, T2 b) {
    bool compare = a < b;
    if(compare) a = b;
    return compare;
}
template<typename T1, typename T2> inline bool chmin(T1 &a, T2 b) {
    bool compare = a > b;
    if(compare) a = b;
    return compare;
}

int dx[4] = {-1,0,1,0};
int dy[4] = {0,1,0,-1};

vector<vector<pii>> G;
vi dist;
vi base2(10,0);
vb visited;

void check(int x) {
    for (int i = 9; i >= 0; i--) {
        if ((x & (1 << i)) == 0) continue;
        if (base2[i] == 0) {
            base2[i] = x;
            return;
        }
        x ^= base2[i];
    }
}
    
int get_answer(int x) {
    for (int i = 9; i >= 0; i--) {
        if (base2[i] != 0) {
            x = min(x, x ^ base2[i]);
        }
    }
    return x;
}

int main(void){
    int N, M;
    cin >> N >> M;
    
    G.resize(N + 1);
    
    for (int i = 0; i < M; i++) {
        int a, b, w;
        cin >> a >> b >> w;
        G[a].push_back({b, w});
    }
    
    dist.resize(N+1, -1);
    dist[1] = 0;
    queue<int> q;
    q.push(1);
    
    while (!q.empty()) {
        int v = q.front();
        q.pop();
        
        for (auto& e : G[v]) {
            int next_v = e.first;
            int weight = e.second;
            
            if (dist[next_v] == -1) {
                dist[next_v] = dist[v] ^ weight;
                q.push(next_v);
            }
        }
    }
    
    if (dist[N] == -1) {
        cout << -1 << endl;
        return 0;
    }
    
    visited.resize(N + 1, false);
    
    for (int v = 1; v <= N; v++) {
        if (dist[v] != -1) {  
            for (auto e : G[v]) {
                int next_v = e.first;
                int weight = e.second;
                if (dist[next_v] != -1) {
                    int cycle_xor = dist[v] ^ weight ^ dist[next_v];
                    if (cycle_xor != 0) {
                        check(cycle_xor);
                    }
                }
            }
        }
    }
    
    int result = get_answer(dist[N]);
    cout << result << endl;
    
    return 0;
}

Submission Info

Judge Result