Submission #736118

#	Time	Username	Problem	Language	Result	Execution time	Memory
736118		nguyentunglam	Passport (JOI23_passport)	C++17	100 / 100	862 ms	85324 KiB

passport

#include<bits/stdc++.h>
#define fi first
#define se second
#define endl "\n"
#define ii pair<int, int>
using namespace std;
const int N = 8e5 + 10;
int f[N], g[N], h[N], p[N];
bool mark[N];
vector<ii> adj[N];
priority_queue<ii, vector<ii>, greater<ii> > q;
void calc(int start, int d[]) {
    d[start] = 0;
    q.push({0, start});
    while (!q.empty()) {
        int cost, u; tie(cost, u) = q.top(); q.pop();
        if (d[u] != cost) continue;
        for(auto &[v, w] : adj[u]) if (d[v] > d[u] + w) d[v] = d[u] + w, q.push({d[v], v});
    }
}

void init(int s, int l, int r) {
    if (l == r) {
        mark[s] = 1;
        p[l] = s;
        return;
    }
    adj[s << 1].emplace_back(s, 0);
    adj[s << 1 | 1].emplace_back(s, 0);
    int mid = l + r >> 1;
    init(s << 1, l, mid);
    init(s << 1 | 1, mid + 1, r);
}

void add(int s, int l, int r, int from, int to, int idx) {
    if (l > to || r < from) return;
    if (from <= l && r <= to) {
        adj[s].emplace_back(p[idx], 1);
        return;
    }
    int mid = l + r >> 1;
    add(s << 1, l, mid, from, to, idx);
    add(s << 1 | 1, mid + 1, r, from, to, idx);
}

int main() {
    #define task ""
    cin.tie(0) -> sync_with_stdio(0);
    if (fopen ("task.inp", "r")) {
        freopen ("task.inp", "r", stdin);
        freopen ("task.out", "w", stdout);
    }
    if (fopen (task".inp", "r")) {
        freopen (task".inp", "r", stdin);
        freopen (task".out", "w", stdout);
    }

    int n; cin >> n;
    init(1, 1, n);
    for(int i = 1; i <= n; i++) {
        int l, r; cin >> l >> r;
        add(1, 1, n, l, r, i);
    }
    for(int i = 1; i <= 4 * n; i++) f[i] = g[i] = 1e9;
    calc(p[1], f);
    calc(p[n], g);

    for(int i = 1; i <= 4 * n; i++) {
        if (i == p[1] || i == p[n]) h[i] = f[i] + g[i];
        else h[i] = f[i] + g[i] - mark[i];
        q.push({h[i], i});
    }

    while (!q.empty()) {
        int cost, u; tie(cost, u) = q.top(); q.pop();
        if (cost != h[u]) continue;
        for(auto &[v, w] : adj[u]) if (h[v] > h[u] + w) {
            h[v] = h[u] + w;
            q.push({h[v], v});
        }
    }

    for(int i = 1; i <= 4 * n; i++) if (h[i] > 1e8) h[i] = -1;

    int q; cin >> q;
    while (q--) {
        int x; cin >> x;
        cout << h[p[x]] << endl;
    }
}

Compilation message (stderr)

passport.cpp: In function 'void init(int, int, int)':
passport.cpp:30:17: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   30 |     int mid = l + r >> 1;
      |               ~~^~~
passport.cpp: In function 'void add(int, int, int, int, int, int)':
passport.cpp:41:17: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   41 |     int mid = l + r >> 1;
      |               ~~^~~
passport.cpp: In function 'int main()':
passport.cpp:50:17: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   50 |         freopen ("task.inp", "r", stdin);
      |         ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
passport.cpp:51:17: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   51 |         freopen ("task.out", "w", stdout);
      |         ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
passport.cpp:54:17: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   54 |         freopen (task".inp", "r", stdin);
      |         ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
passport.cpp:55:17: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   55 |         freopen (task".out", "w", stdout);
      |         ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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