oj.uz

Submission #866756

# Submission time Handle Problem Language Result Execution time Memory
866756 2023-10-27T02:33:04 Z _anhxinloi_ One-Way Streets (CEOI17_oneway) C++14
100 / 100
 55 ms 22996 KB 
#include<bits/stdc++.h>
#define int long long
#define fi first
#define se second

using namespace std;

const int maxn = 1e5 + 5;
const int inf = 1e18;
typedef pair<int, int> pii;

int low[maxn], num[maxn], tds, scc;
int lab[maxn], n, m, d[maxn], q;
char s[maxn];
stack<int> st;
vector<int> adj[maxn], g[maxn];
pii canh[maxn];
bool check[maxn];

void dfs(int u, int par)
{
    low[u] = num[u] = ++tds;
    st.push(u);
    int tds = 0;
    for(int v : adj[u]){
        if(v != par || tds == 1){
            if(num[v] != 0)
                low[u] = min(low[u], num[v]);
            else{
                dfs(v, u);
                low[u] = min(low[u], low[v]);
            }
        }
        else{
            tds++;
        }
    }

    if(low[u] >= num[u]){
        scc++;
        int tmp;
        do
        {
            tmp = st.top();
            st.pop();
            lab[tmp] = scc;
            for (int w: adj[tmp]) {
                if (lab[w] && scc != lab[w]) g[scc].push_back(lab[w]);
            }
            low[tmp] = num[tmp] = inf;
        }while(tmp != u);
    }
}

void dfs_work(int u)
{
    check[u] = true;
    for(int v : g[u]){
        if(!check[v])
            dfs_work(v);
        d[u] += d[v];
    }
}

signed main()
{
//    freopen("oneway.inp" , "r" , stdin);
//    freopen("oneway.out" , "w" , stdout);

    ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);

    cin >> n >> m;
    for(int i=1 ; i<=m ; ++i){
        int u, v;   cin >> u >> v;
        adj[u].push_back(v);
        adj[v].push_back(u);
        canh[i] = {u, v};
    }

    for(int i=1 ; i<=n ; ++i){
        if(!num[i]){
            dfs(i, 0);
        }
    }

//    for(int i=1 ; i<=m ; ++i){
//        auto [u, v] = canh[i];
//        int x = lab[u]; int y = lab[v];
//        if(x != y){
//            g[x].push_back(y);
//        }
//    }

    cin >> q;
    for(int i=1 ; i<=q ; ++i){
        int u, v;   cin >> u >> v;
        u = lab[u]; v = lab[v];
        d[v]--; d[u]++;
    }

    for(int i=1 ; i<=scc ; ++i){
        if(!check[i]){
            dfs_work(i);
        }
    }

    for(int i=1 ; i<=m ; ++i){
        auto [u, v] = canh[i];
        int x = lab[u]; int y = lab[v];

        if(x == y){
            s[i] = 'B';
        }

        if(x > y)
        {
            if(d[y] > 0)    s[i] = 'L';
            if(d[y] < 0)    s[i] = 'R';
            if(d[y] == 0)   s[i] = 'B';
        }

        if(x < y)
        {
            if(d[x] > 0)    s[i] = 'R';
            if(d[x] < 0)    s[i] = 'L';
            if(d[x] == 0)   s[i] = 'B';
        }
    }

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

/// code by yourlove ///

Compilation message

oneway.cpp: In function 'int main()':
oneway.cpp:108:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
  108 |         auto [u, v] = canh[i];
      |              ^

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 8540 KB Output is correct
2 Correct 1 ms 8540 KB Output is correct
3 Correct 2 ms 8540 KB Output is correct
4 Correct 2 ms 8540 KB Output is correct
5 Correct 2 ms 8796 KB Output is correct
6 Correct 2 ms 8540 KB Output is correct
7 Correct 2 ms 8540 KB Output is correct
8 Correct 2 ms 8540 KB Output is correct
9 Correct 2 ms 8536 KB Output is correct
10 Correct 2 ms 8536 KB Output is correct

Subtask #2
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 8540 KB Output is correct
2 Correct 1 ms 8540 KB Output is correct
3 Correct 2 ms 8540 KB Output is correct
4 Correct 2 ms 8540 KB Output is correct
5 Correct 2 ms 8796 KB Output is correct
6 Correct 2 ms 8540 KB Output is correct
7 Correct 2 ms 8540 KB Output is correct
8 Correct 2 ms 8540 KB Output is correct
9 Correct 2 ms 8536 KB Output is correct
10 Correct 2 ms 8536 KB Output is correct
11 Correct 27 ms 14012 KB Output is correct
12 Correct 30 ms 14940 KB Output is correct
13 Correct 33 ms 16136 KB Output is correct
14 Correct 36 ms 16988 KB Output is correct
15 Correct 39 ms 17348 KB Output is correct
16 Correct 37 ms 16728 KB Output is correct
17 Correct 37 ms 18780 KB Output is correct
18 Correct 36 ms 16900 KB Output is correct
19 Correct 39 ms 19796 KB Output is correct
20 Correct 29 ms 14768 KB Output is correct
21 Correct 28 ms 14340 KB Output is correct

Subtask #3
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 8540 KB Output is correct
2 Correct 1 ms 8540 KB Output is correct
3 Correct 2 ms 8540 KB Output is correct
4 Correct 2 ms 8540 KB Output is correct
5 Correct 2 ms 8796 KB Output is correct
6 Correct 2 ms 8540 KB Output is correct
7 Correct 2 ms 8540 KB Output is correct
8 Correct 2 ms 8540 KB Output is correct
9 Correct 2 ms 8536 KB Output is correct
10 Correct 2 ms 8536 KB Output is correct
11 Correct 27 ms 14012 KB Output is correct
12 Correct 30 ms 14940 KB Output is correct
13 Correct 33 ms 16136 KB Output is correct
14 Correct 36 ms 16988 KB Output is correct
15 Correct 39 ms 17348 KB Output is correct
16 Correct 37 ms 16728 KB Output is correct
17 Correct 37 ms 18780 KB Output is correct
18 Correct 36 ms 16900 KB Output is correct
19 Correct 39 ms 19796 KB Output is correct
20 Correct 29 ms 14768 KB Output is correct
21 Correct 28 ms 14340 KB Output is correct
22 Correct 51 ms 19804 KB Output is correct
23 Correct 55 ms 18164 KB Output is correct
24 Correct 48 ms 18004 KB Output is correct
25 Correct 53 ms 22996 KB Output is correct
26 Correct 49 ms 19408 KB Output is correct
27 Correct 51 ms 18248 KB Output is correct
28 Correct 21 ms 12124 KB Output is correct
29 Correct 43 ms 15388 KB Output is correct
30 Correct 45 ms 15344 KB Output is correct
31 Correct 41 ms 15952 KB Output is correct
32 Correct 49 ms 18512 KB Output is correct