Submission #1336067

#	Time	Username	Problem	Language	Result	Execution time	Memory
1336067		retarde	Railway Trip 2 (JOI22_ho_t4)	C++20	8 / 100	5 ms	344 KiB

Main

#include <bits/stdc++.h>
using namespace std;

#define pb push_back
#define pf push_front
#define mp make_pair
#define fi first
#define se second
#define int long long
#define all(x) (x).begin(), (x).end()

typedef long double ld;
typedef long long ll;
typedef pair<ll,ll> pll;
typedef pair<int,int> pii;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<bool> vb;
typedef vector<vector<int>> vvi;
typedef vector<vector<bool>> vvb;
typedef vector<vector<ll>> vvll;
typedef vector<string> vs;
typedef vector<vector<string>> vvs;
typedef vector<char> vc;
typedef vector<vector<char>> vvc;
typedef map<int, int> mii;
typedef unordered_map<int, int> umii;

const int mod = 1e9 + 7;
const int inf = INTMAX_MAX;
const bool tc = false;

const int mxn = 1e3+5, mxm=2e3+5;

pii lines[mxm];
int r[mxn], l[mxn];

int qr(int lx, int rx) {
    int ans = -1;
    for (int i = lx; i <= rx; i++) ans = max(ans, r[i]);
    return ans;
}

int ql(int lx, int rx) {
    int ans = 1e18;
    for (int i = lx; i <= rx; i++) ans = min(ans, l[i]);
    return ans;
}

inline void solve() {
    int n, k, m;
    cin >> n >> k >> m;
    for (int i = 0; i < m; i++) {cin >> lines[i].fi >> lines[i].se; lines[i].fi--; lines[i].se--;}
    for (int i = 0; i < n; i++) l[i] = r[i] = i;

    for (int i = 0; i < m; i++) {
        auto x = lines[i];
        // cout << lines[i].fi << " " << lines[i].se << '\n';
        if (x.fi < x.se) {
            for (int i = x.fi; i <= min(x.se, x.fi+k-1); i++) {
                r[i] = max(r[i], x.se);
            }
        } else {
            // cout << "h\n";
            // cout << x.fi << " " << max(x.se, x.fi-k+1) << "\n";
            for (int i = x.fi; i >= max(x.se, x.fi-k+1); i--) {
                // cout << i << '\n';
                l[i] = min(l[i], x.se);
            }
        }
        // cout << '\n';
    }

    // for (int i = 0; i < n; i++) cout << l[i] << " ";
    // cout << '\n';
    // for (int i = 0; i < n; i++) cout << r[i] << " ";
    // cout << '\n';

    int q; cin >> q;
    while (q--) {
        int s, t;
        cin >> s >> t;
        s--; t--;
        pii cur = {s, s}, last = {-1, -1};
        int ans = 0; int itr = 0;
        while (cur != last && (itr < 1e9)) {
            if (cur.fi <= t && t <= cur.se) break;
            // cout << cur.fi+1 << " " << cur.se+1 << " h\n";
            last = cur;
            cur = {ql(cur.fi, cur.se), qr(cur.fi, cur.se)};
            itr++;
            ans++;
        }
        cout << (cur == last ? -1 : ans) << '\n';
    }
}

void setIO(string s) {
    freopen((s + ".in").c_str(), "r", stdin);
    freopen((s + ".out").c_str(), "w", stdout);
}

signed main() {
    ios::sync_with_stdio(false);
    cout.tie(0);
    cin.tie(0);
    //setIO();

    int t = 1;
    if (tc) {
        cin >> t;
    }

    while (t--) {
        solve();
    }
}

Compilation message (stderr)

Main.cpp: In function 'void setIO(std::string)':
Main.cpp:99:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   99 |     freopen((s + ".in").c_str(), "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:100:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  100 |     freopen((s + ".out").c_str(), "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 8 / 8
• Subtask 2: 0 / 8
• Subtask 3: 0 / 11
• Subtask 4: 0 / 25
• Subtask 5: 0 / 35
• Subtask 6: 0 / 13