oj.uz

Submission #795228

# Submission time Handle Problem Language Result Execution time Memory
795228 2023-07-27T07:39:23 Z bLIC One-Way Streets (CEOI17_oneway) C++17
100 / 100
 273 ms 56128 KB 
/**
 *  Author: Anil Byar
**/

#include <bits/stdc++.h>
// #include <ext/pb_ds/assoc_container.hpp>
// #include <ext/pb_ds/tree_policy.hpp>

// using namespace __gnu_pbds;
using namespace std;

// template<class T>
// using ordered_set = tree<T, null_type, less_equal<T>, rb_tree_tag, tree_order_statistics_node_update> ordered_set;



#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define sz(x) (int)(x).size()
#define uniq(v) v.erase(unique(all(v)), v.end())
#define ft first
#define sd second
#define pb push_back
#define eb emplace_back

// Source: https://codeforces.com/blog/entry/68809
// { start
void __print(int x) {cerr << x;}
void __print(long x) {cerr << x;}
void __print(long long x) {cerr << x;}
void __print(unsigned x) {cerr << x;}
void __print(unsigned long x) {cerr << x;}
void __print(unsigned long long x) {cerr << x;}
void __print(float x) {cerr << x;}
void __print(double x) {cerr << x;}
void __print(long double x) {cerr << x;}
void __print(char x) {cerr << '\'' << x << '\'';}
void __print(const char *x) {cerr << '"' << x << '"';}
void __print(const string &x) {cerr << '"' << x << '"';}
void __print(bool x) {cerr << (x ? "true" : "false");}

template<typename T, typename V>
void __print(const pair<T, V> &x) {cerr << '{'; __print(x.first); cerr << ','; __print(x.second); cerr << '}';}
template<typename T>
void __print(const T &x) {int f = 0; cerr << '{'; for (auto &i: x) cerr << (f++ ? "," : ""), __print(i); cerr << "}";}
void _print() {cerr << "]\n";}
template <typename T, typename... V>
void _print(T t, V... v) {__print(t); if (sizeof...(v)) cerr << ", "; _print(v...);}
#ifndef ONLINE_JUDGE
#define debug(x...) cerr << "[" << #x << "] = ["; _print(x)
#else
#define debug(x...)
#endif
// } end


typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef vector<int> vi;
typedef vector<pii> vii;
typedef vector<ll> vl;
typedef vector<pll> vll;
typedef vector<vi> vvi;
typedef vector<vii> vvii;
typedef vector<vl> vvl;

#define dbg if(0)

const ll MOD = 1e9+7;
const ll MOD9 = 998244353;
const ll INFLL = 1e18+5;
const int INF = 1e9;

void printbit(int x, int len) {string s="\n";while(len--){s=((x%2)?'1':'0')+s;x/=2;} cout<<s;}
ll power(ll x, ll y, ll mod){if (y==0) return 1;ll ret = power(x, y/2, mod);ret *= ret;ret%=mod;if (y&1) ret *= x;return ret%mod;}
ll modinv(ll x, ll mod = MOD) {return power(x, mod-2, mod);}

template<class T> bool chmin(T& a, T b){return (a>b?a=b,1:0);}
template<class T> bool chmax(T& a, T b){return (a<b?a=b,1:0);}
template<class T>
istream& operator>>(istream&in, vector<T>&v){
    for (T& x:v) in>>x;
    return in;
}
template<class T>
ostream& operator<<(ostream&out, vector<T>&v){
    for (T& x:v) out<<x<<' ';
    cout<<'\n';
    return out;
}
// use ?: with brackets (?:)
// check for overflow
// think about dp
// Read the statement carefully

struct Edge{
    int to, id;// wt
    bool dir;
};

const int N = 1e5;

vector<Edge> adj[N];
bool visNode[N];
bool visEdge[N];

int dpUp[N];

set<int> startsends[N];
string ans;

void dfs(int node, int edgeId, bool dir){
    visNode[node] = true;
    // debug(node);
    for (Edge e:adj[node]){
        
        // handles cases of multiple edges
        if (e.id==edgeId) continue;
        if (!visEdge[e.id]){
            visEdge[e.id] = true;
            if (!visNode[e.to]){
                dfs(e.to, e.id, e.dir);
                dpUp[node] += dpUp[e.to];

                if (sz(startsends[node])<sz(startsends[e.to])) swap(startsends[node], startsends[e.to]);
                for (int x:startsends[e.to]) {
                    if (startsends[node].count(-x)) startsends[node].erase(-x);
                    else startsends[node].insert(x);
                }
            } else {
                dpUp[node]++;
                ans[e.id] = 'B';
            }
        } else {
            dpUp[node]--;
        }
    }
    if (edgeId!=-1){
        if (sz(startsends[node])==0 || dpUp[node]) ans[edgeId] = 'B';
        else ans[edgeId] = ((dir^(*startsends[node].begin()<0))?'R':'L');
    }
    // debug(node, dpUp[node], startsends[node]);
}


void solve(){
    int n, m;cin>>n>>m;
    ans.resize(m,'\0');
    for (int i = 0;i<m;i++){
        int u, v;cin>>u>>v;
        u--;v--;
        adj[u].push_back({v, i, 0}); // u -> v
        adj[v].push_back({u, i, 1}); // v -> u
    }
    int q;cin>>q;
    for (int i = 0;i<q;i++) {
        int u, v;cin>>u>>v;
        u--;v--;
        if (u==v) continue;
        startsends[u].insert(i+1);  // start
        startsends[v].insert(-i-1); // end
    }
    for (int i = 0;i<n;i++){
        if (!visNode[i]){
            dfs(i, -1, 0);
        }
    }
    cout<<ans;
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);


#define ONLINE_JUDGE
#ifndef ONLINE_JUDGE
    freopen("input.in", "r", stdin);
    freopen("output.out", "w", stdout);
    freopen("debug.dbg", "w", stderr);
    int tt = clock();
#endif

    int t=1, i = 1;
    // cin>>t;
    while(t--){
        // cout<<"Case #"<<i++<<": ";
        solve();
        cout<<'\n';
    }
#ifndef ONLINE_JUDGE
    cerr << "TIME = " << (float)(clock() - tt)/CLOCKS_PER_SEC << endl;
    tt = clock();
#endif
}

Compilation message

oneway.cpp: In function 'int main()':
oneway.cpp:186:14: warning: unused variable 'i' [-Wunused-variable]
  186 |     int t=1, i = 1;
      |              ^

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 7380 KB Output is correct
2 Correct 5 ms 7404 KB Output is correct
3 Correct 4 ms 7380 KB Output is correct
4 Correct 4 ms 7320 KB Output is correct
5 Correct 4 ms 7380 KB Output is correct
6 Correct 3 ms 7380 KB Output is correct
7 Correct 3 ms 7380 KB Output is correct
8 Correct 4 ms 7380 KB Output is correct
9 Correct 4 ms 7380 KB Output is correct
10 Correct 3 ms 7392 KB Output is correct

Subtask #2
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 7380 KB Output is correct
2 Correct 5 ms 7404 KB Output is correct
3 Correct 4 ms 7380 KB Output is correct
4 Correct 4 ms 7320 KB Output is correct
5 Correct 4 ms 7380 KB Output is correct
6 Correct 3 ms 7380 KB Output is correct
7 Correct 3 ms 7380 KB Output is correct
8 Correct 4 ms 7380 KB Output is correct
9 Correct 4 ms 7380 KB Output is correct
10 Correct 3 ms 7392 KB Output is correct
11 Correct 29 ms 13780 KB Output is correct
12 Correct 30 ms 15060 KB Output is correct
13 Correct 39 ms 16108 KB Output is correct
14 Correct 42 ms 16324 KB Output is correct
15 Correct 44 ms 17356 KB Output is correct
16 Correct 50 ms 13520 KB Output is correct
17 Correct 35 ms 16308 KB Output is correct
18 Correct 34 ms 13456 KB Output is correct
19 Correct 37 ms 18340 KB Output is correct
20 Correct 30 ms 14948 KB Output is correct
21 Correct 29 ms 14472 KB Output is correct

Subtask #3
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 7380 KB Output is correct
2 Correct 5 ms 7404 KB Output is correct
3 Correct 4 ms 7380 KB Output is correct
4 Correct 4 ms 7320 KB Output is correct
5 Correct 4 ms 7380 KB Output is correct
6 Correct 3 ms 7380 KB Output is correct
7 Correct 3 ms 7380 KB Output is correct
8 Correct 4 ms 7380 KB Output is correct
9 Correct 4 ms 7380 KB Output is correct
10 Correct 3 ms 7392 KB Output is correct
11 Correct 29 ms 13780 KB Output is correct
12 Correct 30 ms 15060 KB Output is correct
13 Correct 39 ms 16108 KB Output is correct
14 Correct 42 ms 16324 KB Output is correct
15 Correct 44 ms 17356 KB Output is correct
16 Correct 50 ms 13520 KB Output is correct
17 Correct 35 ms 16308 KB Output is correct
18 Correct 34 ms 13456 KB Output is correct
19 Correct 37 ms 18340 KB Output is correct
20 Correct 30 ms 14948 KB Output is correct
21 Correct 29 ms 14472 KB Output is correct
22 Correct 196 ms 39244 KB Output is correct
23 Correct 257 ms 53504 KB Output is correct
24 Correct 273 ms 56128 KB Output is correct
25 Correct 176 ms 39244 KB Output is correct
26 Correct 227 ms 38512 KB Output is correct
27 Correct 237 ms 44952 KB Output is correct
28 Correct 132 ms 22860 KB Output is correct
29 Correct 220 ms 37676 KB Output is correct
30 Correct 178 ms 37256 KB Output is correct
31 Correct 191 ms 34140 KB Output is correct
32 Correct 156 ms 33944 KB Output is correct