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답안 #914555

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
914555 2024-01-22T10:29:54 Z sleepntsheep One-Way Streets (CEOI17_oneway) C++17
100 / 100
 325 ms 47184 KB 
#include <stack>
#include <iostream>
#include <fstream>
#include <iomanip>
#include <cmath>
#include <cassert>
#include <cstring>
#include <vector>
#include <algorithm>
#include <deque>
#include <set>
#include <utility>
#include <array>
#include <complex>
 
using namespace std;
#define ALL(x) begin(x), end(x)
#define ShinLena cin.tie(nullptr)->sync_with_stdio(false);
#define N 200005
 
int n, m, p;
basic_string<pair<int, int>> g[N];
 
int tin[N], low[N], timer; char ans[N];
int grp[N], twoedgecc;
 
stack<int> sd;
 
void tarjan(int u, int p)
{
    tin[u] = low[u] = ++timer;
    sd.push(u);
 
    for (auto [v, _] : g[u])
    {
        if (v == p)
        {
            p = -1;
            continue;
        }
        if (!tin[v]) tarjan(v, u);
        low[u] = min(low[u], low[v]);
    }
 
    if (tin[u] == low[u])
    {
        int v;
        do grp[v = sd.top()] = twoedgecc, sd.pop();
        while (v != u);
        ++twoedgecc;
    }
}
 
basic_string<pair<int, int> > G[N];
 
int aux[N], sz[N], ch[N], ci[N], P[20][N], hv[N], hveid[N], dep[N];
 
void dfs(int u, int p)
{
    sz[u] = 1;
    P[0][u] = p;
    for (int j = 1; j < 18; ++j) P[j][u] = P[j-1][P[j-1][u]];
    int hvsz = -1;
    for (auto [v, _] : G[u]) if (v != p)
    {
        dep[v] = dep[u] + 1;
        dfs(v, u); sz[u] += sz[v];
        if (sz[v] > hvsz) hv[u] = v, hvsz = sz[v], hveid[u] = _;
    }
}
 
int ctimer;
void hld(int u, int h, int pd)
{
    ci[u] = ctimer++; ch[u] = h; aux[u] = pd;
    if (hv[u]) hld(hv[u], h, hveid[u]);
    for (auto [v, _] : G[u]) if (v != P[0][u] and v != hv[u]) hld(v, v, _);
}
 
int lca(int u, int v)
{
    if (dep[u] < dep[v]) swap(v, u);
    int dt = dep[u] - dep[v];
    for(int j=18;j--;)if(dt&(1<<j))u=P[j][u];
    if(u==v)return u;
    for(int j=18;j--;)if(P[j][u]-P[j][v])u=P[j][u],v=P[j][v];
    return P[0][u];
}
 
char whatt[N<<1], lz[N<<1];
void _push(int v, int l, int r)
{
    if (lz[v])
    {
        whatt[v]=lz[v];
        if (l-r)
        {
            auto m=(l+r)/2,vl=v+1,vr=v+(m-l+1)*2;
            lz[vl]=lz[vr]=lz[v];
        }
        lz[v]=0;
    }
}
 
void _set(int v, int l, int r,int x,int y,int k)
{
    _push(v,l,r);
    if(r<x or y<l)return;
    if(x<=l and r<=y){lz[v]=k;_push(v,l,r);return;}
    auto m=(l+r)/2,vl=v+1,vr=v+(m-l+1)*2;
    _set(vl,l,m,x,y,k);_set(vr,m+1,r,x,y,k);
}
 
char _qry(int v,int l, int r, int p)
{
    _push(v,l,r);
    if(l==r)return whatt[v];
    auto m=(l+r)/2,vl=v+1,vr=v+(m-l+1)*2;
    if(p<=m)return _qry(vl,l,m,p); return _qry(vr,m+1,r,p);
}
 
void updup(int u, int a, int d)
{
    for (; ch[u] != ch[a]; u = P[0][ch[u]]) _set(0, 0, ctimer, ci[ch[u]], ci[u], d);
    _set(0, 0, ctimer, ci[a], ci[u], d);
}
 
int main()
{
    ShinLena;
    cin >> n >> m;
    for (int u, v, i = 1; i <= m; ++i)
        cin >> u >> v, g[u].push_back({v, i}), g[v].push_back({u, -i}), ans[i] = 'B';
 
    for (int i = 1; i <= n; ++i) if (!tin[i]) tarjan(i, -1);
 
    for (int u = 1; u <= n; ++u)
        for (auto [v, eid] : g[u])
            if (eid > 0 and grp[u] != grp[v])
                G[grp[u]].push_back({grp[v], eid}), G[grp[v]].push_back({grp[u], -eid});
 
    for (int i = 0; i < twoedgecc; ++i) sort(ALL(G[i])), G[i].resize(unique(ALL(G[i])) - G[i].begin());
 
    
    for (int i = 0; i < twoedgecc; ++i) if (!sz[i]) dfs(i, -1), hld(i, i, 0);
 
    _set(0, 0, ctimer, 0, ctimer, 'B');
 
    cin >> p;
    for (int x, y, i = 0; i < p; ++i)
    {
        cin >> x >> y;
        if ((x = grp[x]) == (y = grp[y])) continue;
        int a = lca(x, y);
        int X = _qry(0,0,ctimer,ci[a]);
        updup(x, a, 'L');
        updup(y, a, 'R');
        _set(0,0,ctimer,ci[a],ci[a],X);
    }
 
    for (int i = 0; i < twoedgecc; ++i)
    {
        ans[abs(aux[i])] = _qry(0,0,ctimer,ci[i]);
        if (aux[i] < 0)
        {
            aux[i] *= -1;
            if (ans[aux[i]] == 'L') ans[aux[i]] = 'R';
            else if (ans[aux[i]] == 'R') ans[aux[i]] = 'L';
        }
    }
 
    cout << (ans+1);
 
 
    return 0;
}

Compilation message

oneway.cpp: In function 'char _qry(int, int, int, int)':
oneway.cpp:119:5: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
  119 |     if(p<=m)return _qry(vl,l,m,p); return _qry(vr,m+1,r,p);
      |     ^~
oneway.cpp:119:36: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
  119 |     if(p<=m)return _qry(vl,l,m,p); return _qry(vr,m+1,r,p);
      |                                    ^~~~~~

Subtask #1
30.0 / 30.0

# 결과 실행 시간 메모리 Grader output
1 Correct 8 ms 31064 KB Output is correct
2 Correct 7 ms 31068 KB Output is correct
3 Correct 7 ms 31164 KB Output is correct
4 Correct 8 ms 31064 KB Output is correct
5 Correct 8 ms 31068 KB Output is correct
6 Correct 9 ms 31068 KB Output is correct
7 Correct 9 ms 31324 KB Output is correct
8 Correct 9 ms 31064 KB Output is correct
9 Correct 7 ms 31068 KB Output is correct
10 Correct 8 ms 31068 KB Output is correct

Subtask #2
30.0 / 30.0

# 결과 실행 시간 메모리 Grader output
1 Correct 8 ms 31064 KB Output is correct
2 Correct 7 ms 31068 KB Output is correct
3 Correct 7 ms 31164 KB Output is correct
4 Correct 8 ms 31064 KB Output is correct
5 Correct 8 ms 31068 KB Output is correct
6 Correct 9 ms 31068 KB Output is correct
7 Correct 9 ms 31324 KB Output is correct
8 Correct 9 ms 31064 KB Output is correct
9 Correct 7 ms 31068 KB Output is correct
10 Correct 8 ms 31068 KB Output is correct
11 Correct 35 ms 35136 KB Output is correct
12 Correct 38 ms 35836 KB Output is correct
13 Correct 43 ms 36692 KB Output is correct
14 Correct 44 ms 37204 KB Output is correct
15 Correct 64 ms 39196 KB Output is correct
16 Correct 62 ms 39764 KB Output is correct
17 Correct 75 ms 42344 KB Output is correct
18 Correct 69 ms 39764 KB Output is correct
19 Correct 93 ms 44368 KB Output is correct
20 Correct 37 ms 35412 KB Output is correct
21 Correct 38 ms 34896 KB Output is correct

Subtask #3
40.0 / 40.0

# 결과 실행 시간 메모리 Grader output
1 Correct 8 ms 31064 KB Output is correct
2 Correct 7 ms 31068 KB Output is correct
3 Correct 7 ms 31164 KB Output is correct
4 Correct 8 ms 31064 KB Output is correct
5 Correct 8 ms 31068 KB Output is correct
6 Correct 9 ms 31068 KB Output is correct
7 Correct 9 ms 31324 KB Output is correct
8 Correct 9 ms 31064 KB Output is correct
9 Correct 7 ms 31068 KB Output is correct
10 Correct 8 ms 31068 KB Output is correct
11 Correct 35 ms 35136 KB Output is correct
12 Correct 38 ms 35836 KB Output is correct
13 Correct 43 ms 36692 KB Output is correct
14 Correct 44 ms 37204 KB Output is correct
15 Correct 64 ms 39196 KB Output is correct
16 Correct 62 ms 39764 KB Output is correct
17 Correct 75 ms 42344 KB Output is correct
18 Correct 69 ms 39764 KB Output is correct
19 Correct 93 ms 44368 KB Output is correct
20 Correct 37 ms 35412 KB Output is correct
21 Correct 38 ms 34896 KB Output is correct
22 Correct 243 ms 42448 KB Output is correct
23 Correct 325 ms 40528 KB Output is correct
24 Correct 303 ms 39760 KB Output is correct
25 Correct 223 ms 47184 KB Output is correct
26 Correct 248 ms 42220 KB Output is correct
27 Correct 323 ms 40556 KB Output is correct
28 Correct 28 ms 33112 KB Output is correct
29 Correct 64 ms 34896 KB Output is correct
30 Correct 86 ms 35152 KB Output is correct
31 Correct 63 ms 35408 KB Output is correct
32 Correct 158 ms 38484 KB Output is correct