Submission #1005680

#	Time	Username	Problem	Language	Result	Execution time	Memory
1005680		Rifal	One-Way Streets (CEOI17_oneway)	C++14	0 / 100	1 ms	3676 KiB

oneway

#include <bits/stdc++.h>
#include <fstream>
#include<ext/pb_ds/assoc_container.hpp>
#include<ext/pb_ds/tree_policy.hpp>
#define endl '\n'
#define mod 1000000007
#define INF 1000000000
#define INF2 2000000000
#define fi first
#define se second
using namespace std;
double const EPS = 1e-14;
const int P = 1007;
typedef long long ll;
using namespace __gnu_pbds;
typedef long long ll;
typedef tree<int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update> ordered_set; // find_by_order, order_of_key
const int Max = 1e5 + 5;
vector<int> v[Max];
int sta[Max], low[Max], par[Max];
int tim = 0, nod = 0;
map<pair<int,int>,int> mp, check;
bool vis[Max], ok = false;
void dfs(int s, int p) {
    tim++;
    vis[s] = 1;
    sta[s] = tim;
    low[s] = tim;
    for(auto i : v[s]) {
        if(vis[i] == 0) {
            dfs(i,s);
            low[s] = min(low[s],low[i]);
            if(low[i] > sta[s]) {
                check[{i,s}] = 1;
                check[{s,i}] = 1;
            }
        }
        else if(i != p || par[s] > 0){
            low[s] = min(sta[i],low[s]);
        }
        else if(i == p) {
            par[s]++;
        }
        
    }
}
void dfs2(int s) {
    vis[s] = 1;
    if(s == nod) {
        ok = true; return;
    }
    for(auto i : v[s]) {
        if(vis[i] == 0 && ok == false) {
            dfs2(i);
            if(ok) {
                if(check[{s,i}] == 1) {
                    mp[{s,i}] = 2;
                    mp[{i,s}] = 3;
                }
            }
        }
    }

}
int main()
{
    ios_base::sync_with_stdio(0);cout.tie(0);cin.tie(0);
    int n, m; cin >> n >> m;
    pair<int,int> edge[m];
    for(int i = 0; i < m; i++) {
        int a, b; cin >> a >> b;
        edge[i].fi = a, edge[i].se = b;
        v[a].push_back(b);
        v[b].push_back(a);
    }
    dfs(1,0);
    int p; cin >> p;
    while(p--) {
        int a, b; cin >> a >> b;
        nod = b;
        for(int i = 1; i <= n; i++) vis[i] = 0;
        dfs2(a);
    }
    for(int i = 0; i < m; i++) {
        if(mp[{edge[i].fi,edge[i].se}] == 0) cout << 'B';
        else if(mp[{edge[i].fi,edge[i].se}] == 3) cout << 'L';
        else cout << 'R';
    }
    cout << endl;
    return 0;
}

• Subtask 1: 0 / 30
• Subtask 2: 0 / 30
• Subtask 3: 0 / 40