Submission #1054244

#	Time	Username	Problem	Language	Result	Execution time	Memory
1054244		manhlinh1501	Bitaro’s Party (JOI18_bitaro)	C++17	0 / 100	2048 ms	18776 KiB

bitaro

#include <bits/stdc++.h>
using namespace std;
using pii = pair<int, int>;
using i64 = long long;
const int MAXN = 2e5 + 5;
const int BLOCK_SIZE = 470;

int N, M, Q;
vector<int> adj[MAXN];
vector<int> radj[MAXN];
bool is_deleted[MAXN];
vector<pii> dp[MAXN];

int DFS(int u, int dist) {
    int res = (is_deleted[u] == true ? -1 : dist);
    for(int v : radj[u]) {
        res = max(res, DFS(v, dist + 1));
    }
    return res;
}

vector<pii> merge_vector(vector<pii> a, vector<pii> b) {
    int x = 0, y = 0;
    for(auto &[x, y] : b)
        x++;
    vector<pii> ans;
    while(x < a.size() and y < b.size() and ans.size() < BLOCK_SIZE) {
        if(a[x].first > b[y].first)
            ans.emplace_back(a[x++]);
        else
            ans.emplace_back(b[y++]);
    }
    while(x < a.size() and ans.size() < BLOCK_SIZE)
        ans.emplace_back(a[x++]);
    while(y < b.size() and ans.size() < BLOCK_SIZE)
        ans.emplace_back(b[y++]);
    return ans;
}

signed main() {
#define TASK "code"

    if (fopen(TASK ".inp", "r")) {
        freopen(TASK ".inp", "r", stdin);
        freopen(TASK ".out", "w", stdout);
    }

    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

    cin >> N >> M >> Q;
    for(int i = 1; i <= M; i++) {
        int u, v;
        cin >> u >> v;
        adj[u].emplace_back(v);
        radj[v].emplace_back(u);
    }
    for(int u = 1; u <= N; u++) {
        dp[u].emplace_back(0, u);
        for(int v : radj[u])
            dp[u] = merge_vector(dp[u], dp[v]);
    }
    while(Q--) {
        int u;
        cin >> u;
        int sz;
        cin >> sz;
        vector<int> a(sz, 0);
        for(int &x : a) cin >> x;
        for(int x : a) is_deleted[x] = true;
        if(a.size() >= BLOCK_SIZE - 1)
            cout << DFS(u, 0) << "\n";
        else {
            int ans = -1;
            for(auto [x, y] : dp[u]) {
                if(is_deleted[y] == false) ans = max(ans, x);
            }
            cout << ans << "\n";
        }
        for(int x : a) is_deleted[x] = false;
    }
    return (0 ^ 0);
}

Compilation message (stderr)

bitaro.cpp: In function 'std::vector<std::pair<int, int> > merge_vector(std::vector<std::pair<int, int> >, std::vector<std::pair<int, int> >)':
bitaro.cpp:27:13: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   27 |     while(x < a.size() and y < b.size() and ans.size() < BLOCK_SIZE) {
      |           ~~^~~~~~~~~~
bitaro.cpp:27:30: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   27 |     while(x < a.size() and y < b.size() and ans.size() < BLOCK_SIZE) {
      |                            ~~^~~~~~~~~~
bitaro.cpp:33:13: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   33 |     while(x < a.size() and ans.size() < BLOCK_SIZE)
      |           ~~^~~~~~~~~~
bitaro.cpp:35:13: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   35 |     while(y < b.size() and ans.size() < BLOCK_SIZE)
      |           ~~^~~~~~~~~~
bitaro.cpp: In function 'int main()':
bitaro.cpp:44:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   44 |         freopen(TASK ".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
bitaro.cpp:45:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   45 |         freopen(TASK ".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 7
• Subtask 2: 0 / 7
• Subtask 3: 0 / 86