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답안 #1003764

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
1003764 2024-06-20T16:58:17 Z vjudge1 One-Way Streets (CEOI17_oneway) C++17
100 / 100
 194 ms 76804 KB 
#pragma GCC optimize("Ofast")
#include"bits/stdc++.h"
#define int long long

using namespace std;

const int sz = 2e5 + 10;
const int sm = 25;

vector<vector<int>> aj[sz], ajgr[sz];
int br[sz], gr[sz], dp[sz];
int in[sz], lo[sz];
int pn[sz], pe[sz];
int le[sz], ri[sz];
int up[sm][sz];
int n, m, p;
bool dr[sz];
char la[sz];
int tr;

void taj(int v, int p = 0) {
    in[v] = lo[v] = ++ tr;
    bool ps = false;
    for (auto& u : aj[v]) {
        int to = u[0], nm = u[1];
        if (to == p && !ps) {
            ps = true;
            continue;
        } else if (in[to]) {
            lo[v] = min(lo[v], in[to]);
        } else {
            taj(to, v);
            lo[v] = min(lo[v], lo[to]);
            if (lo[to] > in[v]) {
                br[nm] = true;
            }
        }
    }
}

void cmp(int v, int gn) {
    gr[v] = gn;
    for (auto& u : aj[v]) {
        int to = u[0], nm = u[1];
        if (!gr[to] && !br[nm]) {
            cmp(to, gn);
        }
    }
}

void dpt(int v, int p = 0, int d = 1) {
    up[0][v] = pn[v];
    dp[v] = d;
    for (auto& u : ajgr[v]) {
        int to = u[0], nm = u[1];
        if (to != p) {
            pn[to] = v;
            pe[to] = nm;
            dpt(to, v, d + 1);
        }
    }
}

int lca(int a, int b) {
    if (dp[a] > dp[b]) {
        swap(a, b);
    }
    int d = dp[b] - dp[a];
    for (int i = 0; i < sm; i ++) {
        if (d & (1ll << i)) {
            b = up[i][b];
        }
    }
    if (a == b) {
        return a;
    }
    for (int i = sm - 1; i >= 0; i--) {
        if (up[i][a] != up[i][b]) {
            a = up[i][a];
            b = up[i][b];
        }
    }
    return up[0][a];
}

void gdr(int a, int b, int d) {
    if (a == b) {
        return;
    }
    if (!dr[a]) {
        dr[a] = true;
        int to = pn[a];
        int nm = pe[a];
        int gna = gr[le[nm]];
        if (0 == d) {
            if (gna == a) {
                la[nm] = 'R';
            } else {
                la[nm] = 'L';
            }
        } else {
            if (gna == a) {
                la[nm] = 'L';
            } else {
                la[nm] = 'R';
            }
        }
        gdr(to, b, d);
    }
}

signed main() {
    cin.tie(nullptr)->sync_with_stdio(false);

    cin >> n >> m;

    for (int i = 1; i <= m; i ++) {
        int a, b;
        cin >> a >> b;

        aj[a].push_back({b, i});
        aj[b].push_back({a, i});
        le[i] = a;
        ri[i] = b;
        la[i] = 'B';
    }

    for (int i = 1; i <= n; i ++) {
        if (!in[i]) {
            taj(i);
        }
    }

    int gn = 0;

    for (int i = 1; i <= n; i ++) {
        if (!gr[i]) {
            cmp(i, ++ gn);
        }
    }

    for (int i = 1; i <= m; i ++) {
        if (br[i]) {
            int gna = gr[le[i]];
            int gnb = gr[ri[i]];
            ajgr[gna].push_back({gnb, i});
            ajgr[gnb].push_back({gna, i});
        }
    }

    for (int i = 1; i <= gn; i ++) {
        if (!dp[i]) {
            dpt(i);
        }
    }

    for (int i = 1; i < sm; i ++) {
        for (int j = 1; j <= gn; j ++) {
            up[i][j] = up[i - 1][up[i - 1][j]];
        }
    }

    vector<vector<int>> ord;

    int q;
    cin >> q;

    while (q --) {
        int a, b;
        cin >> a >> b;

        a = gr[a];
        b = gr[b];
        int l = lca(a, b);
        ord.push_back({dp[l], a, b, l});
    }

    sort(begin(ord), end(ord));

    for (auto& i : ord) {
        int a = i[1];
        int b = i[2];
        int l = i[3];
        gdr(a, l, 0);
        gdr(b, l, 1);
    }

    for (int i = 1; i <= m; i ++) {
        cout << la[i];
    }

    cout << '\n';
}

Subtask #1
30.0 / 30.0

# 결과 실행 시간 메모리 Grader output
1 Correct 7 ms 10076 KB Output is correct
2 Correct 5 ms 10076 KB Output is correct
3 Correct 5 ms 10328 KB Output is correct
4 Correct 6 ms 10588 KB Output is correct
5 Correct 7 ms 10584 KB Output is correct
6 Correct 5 ms 10076 KB Output is correct
7 Correct 6 ms 10584 KB Output is correct
8 Correct 6 ms 10588 KB Output is correct
9 Correct 5 ms 10076 KB Output is correct
10 Correct 6 ms 10076 KB Output is correct

Subtask #2
30.0 / 30.0

# 결과 실행 시간 메모리 Grader output
1 Correct 7 ms 10076 KB Output is correct
2 Correct 5 ms 10076 KB Output is correct
3 Correct 5 ms 10328 KB Output is correct
4 Correct 6 ms 10588 KB Output is correct
5 Correct 7 ms 10584 KB Output is correct
6 Correct 5 ms 10076 KB Output is correct
7 Correct 6 ms 10584 KB Output is correct
8 Correct 6 ms 10588 KB Output is correct
9 Correct 5 ms 10076 KB Output is correct
10 Correct 6 ms 10076 KB Output is correct
11 Correct 44 ms 27496 KB Output is correct
12 Correct 49 ms 29152 KB Output is correct
13 Correct 56 ms 31572 KB Output is correct
14 Correct 69 ms 39472 KB Output is correct
15 Correct 80 ms 42760 KB Output is correct
16 Correct 108 ms 63568 KB Output is correct
17 Correct 109 ms 65364 KB Output is correct
18 Correct 118 ms 63428 KB Output is correct
19 Correct 99 ms 66388 KB Output is correct
20 Correct 53 ms 28256 KB Output is correct
21 Correct 39 ms 28996 KB Output is correct

Subtask #3
40.0 / 40.0

# 결과 실행 시간 메모리 Grader output
1 Correct 7 ms 10076 KB Output is correct
2 Correct 5 ms 10076 KB Output is correct
3 Correct 5 ms 10328 KB Output is correct
4 Correct 6 ms 10588 KB Output is correct
5 Correct 7 ms 10584 KB Output is correct
6 Correct 5 ms 10076 KB Output is correct
7 Correct 6 ms 10584 KB Output is correct
8 Correct 6 ms 10588 KB Output is correct
9 Correct 5 ms 10076 KB Output is correct
10 Correct 6 ms 10076 KB Output is correct
11 Correct 44 ms 27496 KB Output is correct
12 Correct 49 ms 29152 KB Output is correct
13 Correct 56 ms 31572 KB Output is correct
14 Correct 69 ms 39472 KB Output is correct
15 Correct 80 ms 42760 KB Output is correct
16 Correct 108 ms 63568 KB Output is correct
17 Correct 109 ms 65364 KB Output is correct
18 Correct 118 ms 63428 KB Output is correct
19 Correct 99 ms 66388 KB Output is correct
20 Correct 53 ms 28256 KB Output is correct
21 Correct 39 ms 28996 KB Output is correct
22 Correct 191 ms 73472 KB Output is correct
23 Correct 194 ms 71944 KB Output is correct
24 Correct 185 ms 71680 KB Output is correct
25 Correct 164 ms 76804 KB Output is correct
26 Correct 183 ms 72956 KB Output is correct
27 Correct 182 ms 71912 KB Output is correct
28 Correct 51 ms 31160 KB Output is correct
29 Correct 81 ms 36096 KB Output is correct
30 Correct 88 ms 36604 KB Output is correct
31 Correct 84 ms 36396 KB Output is correct
32 Correct 113 ms 49192 KB Output is correct