Submission #1096181

#	Time	Username	Problem	Language	Result	Execution time	Memory
1096181		Zero_OP	Bitaro’s Party (JOI18_bitaro)	C++14	0 / 100	3 ms	5208 KiB

bitaro

#include "bits/stdc++.h"

using namespace std;

#define sz(v) (int)v.size()
#define all(v) begin(v), end(v)
#define compact(v) v.erase(unique(all(v)), end(v))

const int MAX = 1e5 + 5;
int SQRT = 350;

int n, m, q, f[MAX];
vector<int> rev[MAX];
vector<pair<int, int>> dp[MAX]; //[dist, u]
bool bad[MAX];

void insert(vector<pair<int, int>> &A, vector<pair<int, int>>& B){
    //B + 1

    vector<pair<int, int>> C;
    int i = 0, j = 0;
    while(i < sz(A) || j < sz(B)){
        if(i == sz(A)) C.push_back({B[j].first + 1, B[j].second}), ++j;
        else if(j == sz(B)) C.push_back(A[i++]);
        else if((A[i].first < B[j].first + 1) || (A[i].first == B[j].first + 1 && A[i].second > B[j].second)) C.push_back({B[j].first + 1, B[j].second}), ++j;
        else C.push_back(A[i++]);
    }

    compact(C);
    A = C;

    if(A.size() > SQRT + 1) A.resize(SQRT + 1);
}

int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);

    freopen("task.inp", "r", stdin);
    freopen("task.out", "w", stdout);

    cin >> n >> m >> q;
    for(int i = 0; i < m; ++i){
        int u, v;
        cin >> u >> v;
        rev[v].push_back(u);
    }

    SQRT = sqrt(n);
    for(int i = 1; i <= n; ++i){
        dp[i].push_back({0, i});
        for(int j : rev[i]){
            insert(dp[i], dp[j]);
        }
    }

//    for(int i = 1; i <= n; ++i){
//        cout << i << " :\n";
//        for(auto j : S[i]) cout << j.first << ' ' << j.second << '\n'; cout << '\n';
//    }

    while(q--){
        int t, y;
        cin >> t >> y;

        vector<int> nodes(y);
        for(int i = 0; i < y; ++i) cin >> nodes[i];

        for(int u : nodes) bad[u] = true;

        if(y > SQRT){
//            cout << "heavy\n";
            fill(f + 1, f + 1 + n, -1e9);
            f[t] = 0;

            for(int i = t; i > 0; --i){
                for(int j : rev[i]){
                    f[j] = max(f[j], f[i] + 1);
                }
            }

            int ans = -1;
            for(int i = t; i > 0; --i){
                if(!bad[i]) ans = max(ans, f[i]);
            }

            cout << ans << '\n';
        } else{
//            cout << "light\n";
            int ans = -1;
            for(auto u : dp[t]){
                if(!bad[u.second]){
                    ans = u.first;
                    break;
                }
            }

            if(ans == -1){
                cout << ans << '\n';
            } else{
                cout << ans << '\n';
            }
        }

        for(int u : nodes) bad[u] = false;
    }

    return 0;
}
/*


test 1 :
5 6 3
1 2
2 4
3 4
1 3
3 5
4 5
4 1 1
5 2 2 3
2 3 1 4 5

test 2 :
12 17 10
1 2
2 3
3 4
1 5
2 6
3 7
4 8
5 6
6 7
7 8
5 9
6 10
7 11
8 12
9 10
10 11
11 12
6 3 1 7 12
3 7 1 2 3 4 5 6 7
11 3 1 3 5
9 2 1 9
8 4 1 2 3 4
1 1 1
12 0
10 3 1 6 10
11 8 2 3 5 6 7 9 10 11
8 7 2 3 4 5 6 7 8

test 3 :
12 17 1
1 2
2 3
3 4
1 5
2 6
3 7
4 8
5 6
6 7
7 8
5 9
6 10
7 11
8 12
9 10
10 11
11 12
12 0
*/

Compilation message (stderr)

bitaro.cpp: In function 'void insert(std::vector<std::pair<int, int> >&, std::vector<std::pair<int, int> >&)':
bitaro.cpp:32:17: warning: comparison of integer expressions of different signedness: 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   32 |     if(A.size() > SQRT + 1) A.resize(SQRT + 1);
      |        ~~~~~~~~~^~~~~~~~~~
bitaro.cpp: In function 'int main()':
bitaro.cpp:39:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   39 |     freopen("task.inp", "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
bitaro.cpp:40:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   40 |     freopen("task.out", "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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