Submission #888778

#	Time	Username	Problem	Language	Result	Execution time	Memory
888778		vjudge1	Passport (JOI23_passport)	C++17	16 / 100	2096 ms	50328 KiB

passport

#include <bits/stdc++.h>
using namespace std;
typedef int64_t ll;
#define all(x) x.begin(), x.end()
#define size(x) (int)x.size()

template<class S, class T> 
bool chmin(S &a, const T &b) {
    return (a > b ? (a = b) == b : false);
}
template<class S, class T> 
bool chmax(S &a, const T &b) {
    return (a < b ? (a = b) == b : false);
}
const int inf = 1e9;
const ll INF = 1e18;
const int mod = 998244353;
const int N =  2500;

int n, l[N], r[N];
vector<vector<int>> d(N, vector<int> (N, inf));

void bfs(int init) {
    queue<pair<int, int>> q;
    d[l[init]][r[init]] = 1;
    q.push({l[init], r[init]});
    while (!q.empty()) {
        int L = q.front().first, R = q.front().second;
        q.pop();
        for (int i = L; i <= R; ++i) {
            int new_l = min(L, l[i]), new_r = max(R, r[i]);
            if (chmin(d[new_l][new_r], d[L][R] + 1)) {
                q.push({new_l, new_r});
            }
        }
    }
}

signed main() {
    cin.tie(nullptr)->sync_with_stdio(false);
    cin >> n;
    for (int i = 0; i < n; ++i) {
        cin >> l[i] >> r[i];
        l[i]--, r[i]--;
    }
    int q, x;
    cin >> q >> x;
    bfs(--x);
    cout << (d[0][n - 1] == inf ? -1 : d[0][n - 1]);
}

• Subtask 1: 0 / 6
• Subtask 2: 16 / 16
• Subtask 3: 0 / 24
• Subtask 4: 0 / 8
• Subtask 5: 0 / 46