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Submission #156147

# Submission time Handle Problem Language Result Execution time Memory
156147 2019-10-03T16:49:08 Z ZwariowanyMarcin One-Way Streets (CEOI17_oneway) C++14
100 / 100
 176 ms 22904 KB 
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#define ll long long
#define mp make_pair
#define pb push_back
#define ld long double
#define ss(x) (int) x.size()
#define FOR(i, j, n) for(int i = j; i <= n; ++i)
#define fi first
#define se second
#define cat(x) cerr << #x << " = " << x << endl;
#define ios cin.tie(0); ios_base::sync_with_stdio(0)
  
using namespace std;				

const int nax = 1e5 + 111;		
		
int n, m;
int a, b;
vector <pair<int, int>> v[nax];

int h[nax];
pair<int, int> ed[nax];

int id;
int nr[nax];
bool odw[nax];
int low[nax];
stack <int> stos;

void dfs(int u, int ind) {
	stos.push(u);
	low[u] = h[u];
	odw[u] = 1;
	for(auto it : v[u]) {
		if(it.fi == ind)
			continue;
		if(!odw[it.se]) {
			h[it.se] = h[u] + 1;
			dfs(it.se, it.fi);
			low[u] = min(low[u], low[it.se]);
		}
		else {
			low[u] = min(low[u], h[it.se]);
		}
	}
	if(low[u] == h[u]) {
		id += 1;
		while(!stos.empty() && stos.top() != u) {
			nr[stos.top()] = id;
			stos.pop();
		}
		nr[u] = id;
		stos.pop();
	}		
}

vector <pair<int, int>> graf[nax];
pair<int, int> kraw[nax];
int q;

int sum[nax];
		
void solve(int u, int p = 0, int ind = -1) {
	odw[u] = 1;
	for(auto it : graf[u])
		if(!odw[it.se]) {
			solve(it.se, u, it.fi);
			sum[u] += sum[it.se];
		}
	if(ind != -1 && sum[u] != 0) {
		if(sum[u] > 0)
			kraw[ind] = mp(u, p);
		else
			kraw[ind] = mp(p, u);
	}
}
	

int main() {
	scanf("%d%d", &n, &m);
	FOR(i, 1, m) {
		scanf("%d%d", &a, &b);
		ed[i] = mp(a, b);
		if(a == b) {
			continue;
		}
		v[a].pb(mp(i, b));
		v[b].pb(mp(i, a));
	}
	
	FOR(i, 1, n) 
		if(!odw[i]) 
			dfs(i, -1);
	
	FOR(i, 1, n)
		for(auto it : v[i]) 
			if(nr[i] != nr[it.se]) 
				graf[nr[i]].pb(mp(it.fi, nr[it.se]));
	scanf("%d", &q);
	while(q--) {
		scanf("%d%d", &a, &b);
		if(nr[a] == nr[b])
			continue;
		sum[nr[a]] += 1;
		sum[nr[b]] -= 1;
	}
	
	FOR(i, 1, id)
		odw[i] = 0;
	FOR(i, 1, id)
		if(!odw[i]) 
			solve(i);
		
			
	FOR(i, 1, m) {
		if(kraw[i] == mp(0, 0)) {
			printf("B");
			continue;
		}
		ed[i].fi = nr[ed[i].fi];
		ed[i].se = nr[ed[i].se];
		if(kraw[i] == ed[i])
			printf("R");
		else
			printf("L");
	}
		
	
		
		
	
	
	return 0;
}

Compilation message

oneway.cpp: In function 'int main()':
oneway.cpp:82:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d", &n, &m);
  ~~~~~^~~~~~~~~~~~~~~~
oneway.cpp:84:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d", &a, &b);
   ~~~~~^~~~~~~~~~~~~~~~
oneway.cpp:101:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &q);
  ~~~~~^~~~~~~~~~
oneway.cpp:103:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d", &a, &b);
   ~~~~~^~~~~~~~~~~~~~~~

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 4984 KB Output is correct
2 Correct 6 ms 4984 KB Output is correct
3 Correct 7 ms 5112 KB Output is correct
4 Correct 7 ms 5112 KB Output is correct
5 Correct 7 ms 5240 KB Output is correct
6 Correct 6 ms 5112 KB Output is correct
7 Correct 7 ms 5112 KB Output is correct
8 Correct 7 ms 5112 KB Output is correct
9 Correct 7 ms 5112 KB Output is correct
10 Correct 7 ms 5112 KB Output is correct

Subtask #2
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 4984 KB Output is correct
2 Correct 6 ms 4984 KB Output is correct
3 Correct 7 ms 5112 KB Output is correct
4 Correct 7 ms 5112 KB Output is correct
5 Correct 7 ms 5240 KB Output is correct
6 Correct 6 ms 5112 KB Output is correct
7 Correct 7 ms 5112 KB Output is correct
8 Correct 7 ms 5112 KB Output is correct
9 Correct 7 ms 5112 KB Output is correct
10 Correct 7 ms 5112 KB Output is correct
11 Correct 58 ms 11028 KB Output is correct
12 Correct 66 ms 11896 KB Output is correct
13 Correct 71 ms 13048 KB Output is correct
14 Correct 89 ms 14328 KB Output is correct
15 Correct 108 ms 14832 KB Output is correct
16 Correct 112 ms 16376 KB Output is correct
17 Correct 111 ms 18168 KB Output is correct
18 Correct 116 ms 16880 KB Output is correct
19 Correct 112 ms 19804 KB Output is correct
20 Correct 68 ms 11640 KB Output is correct
21 Correct 62 ms 12152 KB Output is correct

Subtask #3
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 4984 KB Output is correct
2 Correct 6 ms 4984 KB Output is correct
3 Correct 7 ms 5112 KB Output is correct
4 Correct 7 ms 5112 KB Output is correct
5 Correct 7 ms 5240 KB Output is correct
6 Correct 6 ms 5112 KB Output is correct
7 Correct 7 ms 5112 KB Output is correct
8 Correct 7 ms 5112 KB Output is correct
9 Correct 7 ms 5112 KB Output is correct
10 Correct 7 ms 5112 KB Output is correct
11 Correct 58 ms 11028 KB Output is correct
12 Correct 66 ms 11896 KB Output is correct
13 Correct 71 ms 13048 KB Output is correct
14 Correct 89 ms 14328 KB Output is correct
15 Correct 108 ms 14832 KB Output is correct
16 Correct 112 ms 16376 KB Output is correct
17 Correct 111 ms 18168 KB Output is correct
18 Correct 116 ms 16880 KB Output is correct
19 Correct 112 ms 19804 KB Output is correct
20 Correct 68 ms 11640 KB Output is correct
21 Correct 62 ms 12152 KB Output is correct
22 Correct 176 ms 19252 KB Output is correct
23 Correct 139 ms 17912 KB Output is correct
24 Correct 136 ms 18188 KB Output is correct
25 Correct 163 ms 22904 KB Output is correct
26 Correct 137 ms 19316 KB Output is correct
27 Correct 133 ms 18040 KB Output is correct
28 Correct 51 ms 9080 KB Output is correct
29 Correct 92 ms 12408 KB Output is correct
30 Correct 92 ms 12844 KB Output is correct
31 Correct 90 ms 12920 KB Output is correct
32 Correct 103 ms 15996 KB Output is correct