Submission #1007925

#	Time	Username	Problem	Language	Result	Execution time	Memory
1007925		Rifal	One-Way Streets (CEOI17_oneway)	C++14	0 / 100	1 ms	4444 KiB

oneway

#include <bits/stdc++.h>
#define endl '\n'
#define mod 1000000007
#define fi first
#define se second
using namespace std;
typedef long long ll;
const int Max = 1e5 + 5;
vector<int> v[Max];
int sta[Max], low[Max], par[Max];
int tim = 0, cntx = 0, cnty = 0;
map<pair<int,int>,int> mp, check;
bool vis[Max], ok = false;
int okx[Max], oky[Max];
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]) {
                if(cntx > cnty) {
                    mp[{i,s}] = 2;
                    mp[{s,i}] = 3;
                }
                else if(cntx < cnty) {
                    mp[{s,i}] = 2;
                    mp[{i,s}] = 3;
                }
            }
        }
        else if(i != p || par[s] > 0){
            low[s] = min(sta[i],low[s]);
        }
        else if(i == p) {
            par[s]++;
        }
    }
    cntx += okx[s];  cnty += oky[s];
}
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);
    }
    int p; cin >> p;
    while(p--) {
        int a, b; cin >> a >> b;
        okx[a]++; oky[b]++;
    }
    for(int i = 1; i <= n; i++) {
        if(vis[i] == 0) {
            cntx = 0; cnty = 0; dfs(i,0);
        }
    }
    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