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Submission #45456

# Submission time Handle Problem Language Result Execution time Memory
45456 2018-04-14T07:01:40 Z nickyrio One-Way Streets (CEOI17_oneway) C++17
100 / 100
 206 ms 62668 KB 
#include <bits/stdc++.h>
#define FOR(i, a, b) for (int i = (a); i <= (b); ++i)
#define FORD(i, a, b) for (int i = (a); i >= (b); --i)
#define REP(i, a) for (int i = 0; i < (a); ++i)
#define DEBUG(x) { cerr << #x << '=' << x << endl; }
#define Arr(a, l, r) { cerr << #a << " = {"; FOR(_, l, r) cerr << ' ' << a[_]; cerr << "}\n"; }
#define N 1001000
#define pp pair<int, int>
#define endl '\n'
#define IO ios::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL)
#define taskname ""
#define bit(S, i) (((S) >> (i)) & 1)
using namespace std;

int n, m, p, Redge[N];
vector<pp> e[N], newE[N];
int num[N], low[N], cnt, mark[N], nBico;
stack<int> st;
char res[N];

void dfs(int u, int p) {
    num[u] = low[u] = ++cnt;
    st.push(u);
    for(pp x : e[u]) if (x.second != p) {
        int v = x.first;
        if (num[v] == 0) {
            dfs(v, x.second);
            low[u] = min(low[v], low[u]);
            if (low[v] >= num[v]) {
                ++nBico;
                while (true) {
                    int z = st.top(); st.pop();
                    mark[z] = nBico;
                    if (z == v) break;
                }
            }
        } else low[u] = min(low[u], num[v]);
    }
    if (p == -1) {
        ++nBico;
        while (true) {
            int z = st.top(); st.pop();
            mark[z] = nBico;
            if (z == u) break;
        }
    }
}

void NewGraph() {
    FOR(u, 1, n) {
        for (pp x : e[u]) if (mark[u] != mark[x.first]) {
            newE[mark[u]].push_back(pp(mark[x.first], x.second));
        }
    }
}
int w[N];

int visited[N];
void dfs2(int u, int p) {
    visited[u] = 1;
    for (pp x : newE[u]) if (x.second != p) {
        dfs2(x.first, x.second);
        w[u] += w[x.first];
        if (w[x.first] == 0) res[x.second] == 'B';
        else {
            if (w[x.first] > 0) {
                if (mark[Redge[x.second]] == u) res[x.second] = 'R';
                else res[x.second] = 'L';
            }
            else {
                if (mark[Redge[x.second]] == u) res[x.second] = 'L';
                else res[x.second] = 'R';
            }
        }
    }
}

void Solve() {
    cin >> p;
    REP(i, p) {
        int u, v;
        cin >> u >> v;
        if (mark[u] == mark[v]) continue;
        w[mark[u]]++;
        w[mark[v]]--;
    }
    FOR(i, 1, m) res[i] = 'B';
    FOR(i, 1, nBico) if (!visited[i]) dfs2(i, -1);
    FOR(i, 1, m) cout << res[i];
}
int main() {
    #ifdef NERO
    freopen("test.inp","r",stdin);
    freopen("test.out","w",stdout);
    double stime = clock();
    #else
        //freopen(taskname".inp","r",stdin);
        //freopen(taskname".out","w",stdout);
    #endif //NERO
    IO;
    cin >> n >> m;
    FOR(i, 1, m) {
        int u, v;
        cin >> u >> v;
        e[u].push_back(pp(v, i));
        e[v].push_back(pp(u, i));
        Redge[i] = v;
    }
    FOR(i, 1, n) if (num[i] == 0) dfs(i, -1);
    NewGraph();
    //FOR(i, 1, n) cout << i << ' ' << mark[i] << '\n';
    Solve();
    #ifdef NERO
    double etime = clock();
    cerr << "Execution time: " << (etime - stime) / CLOCKS_PER_SEC * 1000 << " ms.\n";
    #endif // NERO
}

Compilation message

oneway.cpp: In function 'void dfs2(int, int)':
oneway.cpp:64:44: warning: statement has no effect [-Wunused-value]
         if (w[x.first] == 0) res[x.second] == 'B';
                              ~~~~~~~~~~~~~~^~~~~~

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 44 ms 47352 KB Output is correct
2 Correct 41 ms 47460 KB Output is correct
3 Correct 42 ms 47664 KB Output is correct
4 Correct 41 ms 47728 KB Output is correct
5 Correct 41 ms 47728 KB Output is correct
6 Correct 41 ms 47728 KB Output is correct
7 Correct 41 ms 47728 KB Output is correct
8 Correct 41 ms 47728 KB Output is correct
9 Correct 51 ms 47728 KB Output is correct
10 Correct 47 ms 47728 KB Output is correct

Subtask #2
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 44 ms 47352 KB Output is correct
2 Correct 41 ms 47460 KB Output is correct
3 Correct 42 ms 47664 KB Output is correct
4 Correct 41 ms 47728 KB Output is correct
5 Correct 41 ms 47728 KB Output is correct
6 Correct 41 ms 47728 KB Output is correct
7 Correct 41 ms 47728 KB Output is correct
8 Correct 41 ms 47728 KB Output is correct
9 Correct 51 ms 47728 KB Output is correct
10 Correct 47 ms 47728 KB Output is correct
11 Correct 96 ms 52444 KB Output is correct
12 Correct 97 ms 53332 KB Output is correct
13 Correct 112 ms 54496 KB Output is correct
14 Correct 125 ms 55808 KB Output is correct
15 Correct 140 ms 56300 KB Output is correct
16 Correct 149 ms 57764 KB Output is correct
17 Correct 154 ms 59140 KB Output is correct
18 Correct 157 ms 59140 KB Output is correct
19 Correct 156 ms 60476 KB Output is correct
20 Correct 99 ms 60476 KB Output is correct
21 Correct 93 ms 60476 KB Output is correct

Subtask #3
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 44 ms 47352 KB Output is correct
2 Correct 41 ms 47460 KB Output is correct
3 Correct 42 ms 47664 KB Output is correct
4 Correct 41 ms 47728 KB Output is correct
5 Correct 41 ms 47728 KB Output is correct
6 Correct 41 ms 47728 KB Output is correct
7 Correct 41 ms 47728 KB Output is correct
8 Correct 41 ms 47728 KB Output is correct
9 Correct 51 ms 47728 KB Output is correct
10 Correct 47 ms 47728 KB Output is correct
11 Correct 96 ms 52444 KB Output is correct
12 Correct 97 ms 53332 KB Output is correct
13 Correct 112 ms 54496 KB Output is correct
14 Correct 125 ms 55808 KB Output is correct
15 Correct 140 ms 56300 KB Output is correct
16 Correct 149 ms 57764 KB Output is correct
17 Correct 154 ms 59140 KB Output is correct
18 Correct 157 ms 59140 KB Output is correct
19 Correct 156 ms 60476 KB Output is correct
20 Correct 99 ms 60476 KB Output is correct
21 Correct 93 ms 60476 KB Output is correct
22 Correct 178 ms 60476 KB Output is correct
23 Correct 166 ms 60476 KB Output is correct
24 Correct 206 ms 60476 KB Output is correct
25 Correct 177 ms 62668 KB Output is correct
26 Correct 166 ms 62668 KB Output is correct
27 Correct 172 ms 62668 KB Output is correct
28 Correct 86 ms 62668 KB Output is correct
29 Correct 120 ms 62668 KB Output is correct
30 Correct 120 ms 62668 KB Output is correct
31 Correct 123 ms 62668 KB Output is correct
32 Correct 130 ms 62668 KB Output is correct