oj.uz

Submission #781256

# Submission time Handle Problem Language Result Execution time Memory
781256 2023-07-13T01:20:57 Z 79brue Making Friends on Joitter is Fun (JOI20_joitter2) C++17
0 / 100
 8 ms 14420 KB 
#include <bits/stdc++.h>

using namespace std;

typedef long long ll;

struct unionFind{
    int n;
    int par[100002];
    ll sz[100002];
    set<int> st[100002]; /// 집합의 원소 종류, 그리고 해당 집합에 edge를 연결한 원소 종류
    set<int> in[100002]; /// x번 집합을 가리키고 있는 집합의 번호
    set<int> out[100002]; /// x번 집합이 가리키고 있는 집합의 번호
    ll ans = 0;

    void init(int _n){
        n = _n;
        for(int i=1; i<=n; i++) par[i] = i, sz[i] = 1, st[i].insert(i);
        ans = 0;
    }

    int find(int x){
        if(x==par[x]) return x;
        return par[x] = find(par[x]);
    }

    queue<pair<int, int> > que;

    void merge(){
        while(!que.empty()){
            int x = que.back().first, y = que.back().second; que.pop();
            x = find(x), y = find(y);
            if(x==y) continue;
            if(st[x].size()+in[x].size()+out[x].size() < st[y].size()+in[y].size()+out[y].size()) swap(x, y);

            /// (tox, x, ytox) -> y, (toy, y, xtoy) -> x
            /// 제거해줘야 하는 것: x, y 안쪽에서의 묶음. 양쪽에 포함된 수는 제거 필요.
            ans += sz[x]*st[y].size() + sz[y]*st[x].size();
            for(int p: st[y]){
                if(st[x].count(p)) ans -= sz[x] + sz[y];
                else st[x].insert(p);
            }

            /// 연결 제거
            in[x].erase(y), in[y].erase(x);
            out[x].erase(y), out[y].erase(x);

            /// 그래프 관리
            for(int p: out[y]){
                in[p].erase(y);
                addEdge(x, p);
            }
            for(int p: in[y]){
                out[p].erase(x);
                addEdge(p, x);
            }
            in[y].clear(), out[y].clear(), st[y].clear();
            par[y] = x, sz[x] += sz[y];
        }
    }

    void addEdge(int x, int y){
        out[x].insert(y);
        in[y].insert(x);
        /// 이걸로 인해 사이클이 생기면 merge
        if(in[x].count(y)){
            que.push(make_pair(x, y));
        }
    }
} dsu;

int n, q;

int main(){
    scanf("%d %d", &n, &q);
    dsu.init(n);
    for(int i=1; i<=q; i++){
        int x, y;
        scanf("%d %d", &x, &y);
        y = dsu.find(y);
        int xp = dsu.find(x);

        /// 이미 같은 컴포넌트 or 이미 가리키고 있음
        if(xp!=y && !dsu.st[y].count(x)){
            dsu.st[y].insert(x);
            dsu.ans += dsu.sz[y];
            x = dsu.find(x);
            dsu.addEdge(x, y);
            while(!dsu.que.empty()) dsu.merge();
        }
        printf("%lld\n", dsu.ans);

//        printf("After query %d: \n", i);
//        for(int i=1; i<=n; i++) {printf("st[%d]: ", i); for(auto j: dsu.st[i]) printf("%d ", j); printf(",\t");} puts("");
//        for(int i=1; i<=n; i++) {printf("in[%d]: ", i); for(auto j: dsu.in[i]) printf("%d ", j); printf(",\t");} puts("");
//        for(int i=1; i<=n; i++) {printf("out[%d]: ", i); for(auto j: dsu.out[i]) printf("%d ", j); printf(",\t");} puts("");
    }
}

Compilation message

joitter2.cpp: In function 'int main()':
joitter2.cpp:75:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   75 |     scanf("%d %d", &n, &q);
      |     ~~~~~^~~~~~~~~~~~~~~~~
joitter2.cpp:79:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   79 |         scanf("%d %d", &x, &y);
      |         ~~~~~^~~~~~~~~~~~~~~~~

Subtask #1
0 / 1.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 14292 KB Output is correct
2 Correct 8 ms 14292 KB Output is correct
3 Correct 6 ms 14360 KB Output is correct
4 Correct 8 ms 14292 KB Output is correct
5 Correct 7 ms 14392 KB Output is correct
6 Correct 6 ms 14340 KB Output is correct
7 Incorrect 7 ms 14420 KB Output isn't correct
8 Halted 0 ms 0 KB -

Subtask #2
0 / 16.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 14292 KB Output is correct
2 Correct 8 ms 14292 KB Output is correct
3 Correct 6 ms 14360 KB Output is correct
4 Correct 8 ms 14292 KB Output is correct
5 Correct 7 ms 14392 KB Output is correct
6 Correct 6 ms 14340 KB Output is correct
7 Incorrect 7 ms 14420 KB Output isn't correct
8 Halted 0 ms 0 KB -

Subtask #3
0 / 83.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 14292 KB Output is correct
2 Correct 8 ms 14292 KB Output is correct
3 Correct 6 ms 14360 KB Output is correct
4 Correct 8 ms 14292 KB Output is correct
5 Correct 7 ms 14392 KB Output is correct
6 Correct 6 ms 14340 KB Output is correct
7 Incorrect 7 ms 14420 KB Output isn't correct
8 Halted 0 ms 0 KB -