제출 #765215

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
765215		oyber	Joker (BOI20_joker)	C++14	0 / 100	105 ms	16568 KiB

Joker

#include <cstdio>
#include <vector>
#include <algorithm>
#include <functional>
using namespace std;

vector<int> u;
vector<int> s;
vector<int> p;

int find(int n) {
    if (u[n] == n) return n;
    return find(u[n]);
}

int parity(int n) {
    if (u[n] == n) return 0;
    return parity(u[n])^p[n];
}

void unite(int a, int b) {
    int ap = find(a);
    int bp = find(b);
    if (s[ap] > s[bp]) {
        swap(a, b);
        swap(ap, bp);
    }
    u[bp] = ap;
    s[ap] += s[bp];
    if (parity(a) == parity(b)) {
        p[b] = 1;
    }
}

int main() {
    int n, m, qn;
    scanf("%d %d %d", &n, &m, &qn);

    u.resize(n);
    s.resize(n, 1);
    p.resize(n);

    for (int i = 0; i < n; i++) {
        u[i] = i;
    }

    vector<vector<int>> e(n);
    for (int i = 0; i < m; i++) {
        int u, v;
        scanf("%d %d", &u, &v);
        u--;v--;
        e[u].push_back(v);
        e[v].push_back(u);
    }

    vector<pair<int, int>> q(qn);
    vector<int> q2(qn);
    for (int i = 0; i < qn; i++) {
        int l, r;
        scanf("%d %d", &l, &r);
        l--;r--;
        q.push_back(make_pair(r, i));
        q2.push_back(r);
    }
    sort(q.begin(), q.end(), greater<pair<int, int>>());

    int cycle = -1;
    for (int j = n-1; j >= 0; j--) {
        for (int k = 0; k < int(e[j].size()); k++) {
            if (e[j][k] > j) {
                int a = j;
                int b = e[j][k];
                if (find(a) == find(b)) {
                    if (parity(a) == parity(b)) {
                        cycle = j;
                        break;
                    }
                } else {
                    unite(a, b);
                }
            }
        }
        if (cycle != -1) break;
    }
    //printf("%d\n", cycle);

    for (int i = 0; i < qn; i++) {
        if (q2[i] <= cycle) {
            printf("YES\n");
        } else {
            printf("NO\n");
        }
    }
}

컴파일 시 표준 에러 (stderr) 메시지

Joker.cpp: In function 'int main()':
Joker.cpp:37:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   37 |     scanf("%d %d %d", &n, &m, &qn);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
Joker.cpp:50:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   50 |         scanf("%d %d", &u, &v);
      |         ~~~~~^~~~~~~~~~~~~~~~~
Joker.cpp:60:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   60 |         scanf("%d %d", &l, &r);
      |         ~~~~~^~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 6
• Subtask 2: 0 / 8
• Subtask 3: 0 / 25
• Subtask 4: 0 / 10
• Subtask 5: 0 / 22
• Subtask 6: 0 / 29