oj.uz

Submission #148090

# Submission time Handle Problem Language Result Execution time Memory
148090 2019-08-31T13:47:11 Z WhipppedCream One-Way Streets (CEOI17_oneway) C++17
100 / 100
 254 ms 30668 KB 
//Power Of Ninja Go
#include <bits/stdc++.h>
//#ifdef atom #else #endif
using namespace std;
typedef long long ll; typedef pair<int, int> ii;
#define X first
#define Y second
#define vi vector<int>
#define vii vector< ii >
#define pb push_back
const int maxn = 1e5+5;
vii adj[maxn];
vii tree[maxn];
ii e[maxn];
bool isB[maxn];
int num[maxn];
int low[maxn];
int bcc[maxn];
int dp[22][maxn];
int ans[maxn];
int link[maxn];
int sw[maxn];
int dep[maxn];
int chil[maxn];
int cnt;
queue<int> Q;
void dfs(int u, int id)
{
    num[u] = low[u] = ++cnt;
    for(auto edge : adj[u])
    {
        int v = edge.X, f = edge.Y;
        if(!num[v])
        {
            dfs(v, f);
            low[u] = min(low[u], low[v]);
            if(low[v]> num[u])
            {
                isB[f] = true;
            }
        }
        else if(f != id) low[u] = min(low[u], num[v]);
    }
}
void play(int u)
{
    bcc[u] = cnt;
    for(auto edge : adj[u])
    {
        int v = edge.X, id = edge.Y;
        if(!isB[id] && !bcc[v]) play(v);
    }
}
void dfsT(int u, int p)
{
    int has = 0;
    for(auto edge : tree[u])
    {
        int v = edge.X, id = edge.Y;
        if(v == p) continue;
        dp[0][v] = u;
        dep[v] = 1+dep[u];
        link[v] = id;
        has = 1;
        dfsT(v, u);
        chil[u]++;
    }
    if(!has) Q.push(u);
}
int LCA(int u, int v)
{
    if(dep[u]< dep[v]) swap(u, v);
    for(int i = 20; i>= 0; i--)
    {
        int k = dp[i][u];
        if(dep[k]>= dep[v]) u = k;
    }
    if(u == v) return u;
    for(int i = 20; i>= 0; i--)
    {
        int a = dp[i][u], b = dp[i][v];
        if(a == b) continue;
        u = a; v = b;
    }
    return dp[0][u];
}
int main()
{
    //#ifndef atom freopen(".in", "r", stdin); freopen(".out", "w", stdout); #endif
    int n, m; cin >> n >> m;
    for(int i = 1; i<= m; i++)
    {
        scanf("%d %d", &e[i].X, &e[i].Y);
        if(e[i].X == e[i].Y) continue;
        adj[e[i].X].pb(ii(e[i].Y, i));
        adj[e[i].Y].pb(ii(e[i].X, i));
    }
    for(int i = 1; i<= n; i++) if(!num[i]) dfs(i, 0);
    //for(int i = 1; i<= m; i++) printf("%d ", isB[i]); printf("\n");
    memset(num, 0, sizeof num);
    cnt = 0;
    for(int i = 1; i<= n; i++) if(!bcc[i]){ cnt++; play(i); }
    //for(int i = 1; i<= n; i++) printf("%d ", bcc[i]); printf("\n");
    for(int i = 1; i<= m; i++)
    {
        if(isB[i])
        {
            int u = e[i].X, v = e[i].Y;
            //printf("(%d, %d) is (%d, %d)\n", u, v, bcc[u], bcc[v]);
            tree[bcc[u]].pb(ii(bcc[v], i));
            tree[bcc[v]].pb(ii(bcc[u], i));
        }
    }
    for(int i = 1; i<= cnt; i++) if(!dep[i]) { dep[i]++; dfsT(i, 0); }
    for(int i = 1; i<= 20; i++)
    {
        for(int j = 1; j<= cnt; j++) dp[i][j] = dp[i-1][dp[i-1][j]];
    }
    int p; cin >> p;
    while(p--)
    {
        int a, b; cin >> a >> b;
        a = bcc[a], b = bcc[b];
        if(a == b) continue;
        sw[a]++; sw[b]--;
    }
    while(!Q.empty())
    {
        int u = Q.front(); Q.pop();
        int p = dp[0][u];
        sw[p] += sw[u];
        chil[p]--;
        if(p && chil[p] == 0) Q.push(p);
        if(sw[u]> 0)
        {
            int id = link[u];
            if(bcc[e[id].X] == u) ans[id] = 1;
            else ans[id] = -1;
        }
        else if(sw[u]< 0)
        {
            int id = link[u];
            if(bcc[e[id].X] == u) ans[id] = -1;
            else ans[id] = 1;
        }
    }
    for(int i = 1; i<= m; i++)
    {
        if(ans[i] == 1) printf("R");
        else if(ans[i] == -1) printf("L");
        else printf("B");
    }
    printf("\n");
}

Compilation message

oneway.cpp: In function 'int main()':
oneway.cpp:93:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d %d", &e[i].X, &e[i].Y);
         ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 5624 KB Output is correct
2 Correct 7 ms 5624 KB Output is correct
3 Correct 7 ms 5624 KB Output is correct
4 Correct 7 ms 5752 KB Output is correct
5 Correct 7 ms 5752 KB Output is correct
6 Correct 7 ms 5624 KB Output is correct
7 Correct 7 ms 5756 KB Output is correct
8 Correct 7 ms 5752 KB Output is correct
9 Correct 7 ms 5624 KB Output is correct
10 Correct 7 ms 5624 KB Output is correct

Subtask #2
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 5624 KB Output is correct
2 Correct 7 ms 5624 KB Output is correct
3 Correct 7 ms 5624 KB Output is correct
4 Correct 7 ms 5752 KB Output is correct
5 Correct 7 ms 5752 KB Output is correct
6 Correct 7 ms 5624 KB Output is correct
7 Correct 7 ms 5756 KB Output is correct
8 Correct 7 ms 5752 KB Output is correct
9 Correct 7 ms 5624 KB Output is correct
10 Correct 7 ms 5624 KB Output is correct
11 Correct 68 ms 11256 KB Output is correct
12 Correct 74 ms 12152 KB Output is correct
13 Correct 84 ms 13660 KB Output is correct
14 Correct 100 ms 17144 KB Output is correct
15 Correct 138 ms 18728 KB Output is correct
16 Correct 131 ms 25864 KB Output is correct
17 Correct 124 ms 27100 KB Output is correct
18 Correct 130 ms 26232 KB Output is correct
19 Correct 126 ms 28024 KB Output is correct
20 Correct 70 ms 11768 KB Output is correct
21 Correct 67 ms 12152 KB Output is correct

Subtask #3
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 5624 KB Output is correct
2 Correct 7 ms 5624 KB Output is correct
3 Correct 7 ms 5624 KB Output is correct
4 Correct 7 ms 5752 KB Output is correct
5 Correct 7 ms 5752 KB Output is correct
6 Correct 7 ms 5624 KB Output is correct
7 Correct 7 ms 5756 KB Output is correct
8 Correct 7 ms 5752 KB Output is correct
9 Correct 7 ms 5624 KB Output is correct
10 Correct 7 ms 5624 KB Output is correct
11 Correct 68 ms 11256 KB Output is correct
12 Correct 74 ms 12152 KB Output is correct
13 Correct 84 ms 13660 KB Output is correct
14 Correct 100 ms 17144 KB Output is correct
15 Correct 138 ms 18728 KB Output is correct
16 Correct 131 ms 25864 KB Output is correct
17 Correct 124 ms 27100 KB Output is correct
18 Correct 130 ms 26232 KB Output is correct
19 Correct 126 ms 28024 KB Output is correct
20 Correct 70 ms 11768 KB Output is correct
21 Correct 67 ms 12152 KB Output is correct
22 Correct 226 ms 28332 KB Output is correct
23 Correct 251 ms 27176 KB Output is correct
24 Correct 240 ms 27384 KB Output is correct
25 Correct 241 ms 30668 KB Output is correct
26 Correct 233 ms 28136 KB Output is correct
27 Correct 254 ms 27128 KB Output is correct
28 Correct 94 ms 9592 KB Output is correct
29 Correct 168 ms 12656 KB Output is correct
30 Correct 166 ms 13048 KB Output is correct
31 Correct 169 ms 12920 KB Output is correct
32 Correct 184 ms 18712 KB Output is correct