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Submission #63224

# Submission time Handle Problem Language Result Execution time Memory
63224 2018-08-01T06:27:40 Z 김세빈(#1833) Alternating Current (BOI18_alternating) C++11
13 / 100
 174 ms 18784 KB 
#include <bits/stdc++.h>

using namespace std;

typedef pair <int, int> pii;

vector <int> L[101010], V[101010];
vector <int> X[101010], Y[101010];
set <int> S;
pii P[101010];
int chk[101010], ans[101010];
int fff[101010];
int n, m;

void die() { printf("impossible\n"); exit(0); }

void dfs(int p, int c)
{
	chk[p] = 2; ans[p] = c;
	for(int &t: V[p]){
		if(chk[t] == 1) dfs(t, !c);
		else if(ans[t] == ans[p]) die();
	}
}

int main()
{
	int i, s, e, x, y, a, b;
	
	scanf("%d%d", &n, &m);
	
	for(i=1; i<=m; i++){
		scanf("%d%d", &a, &b);
		b ++; if(b > n) b -= n;
		P[i] = pii(a, b);
		if(a < b){
			L[a].push_back(i);
			L[b].push_back(-i);
		}
		else{
			L[1].push_back(i);
			L[b].push_back(-i);
			L[a].push_back(i);
		}
	}
	
	for(i=1; i<=n; i++){
		for(int &t: L[i]){
			if(t > 0) S.insert(t);
			else S.erase(-t);
		}
		
		if(S.size() == 2){
			a = *S.begin(); b = *next(S.begin());
			V[a].push_back(b);
			V[b].push_back(a);
			chk[a] = 1; chk[b] = 1;
		}
		else if(S.size() == 1) die();
	}
	
	for(i=1; i<=m; i++){
		if(chk[i] == 1) dfs(i, 0);
	}
	
	x = 1;
	
	for(i=1; i<=m; i++){
		if(chk[i]){
			if(ans[i] == 1) x = i;
		}
	}
	
	ans[x] = 1;
	s = P[x].first;
	
	for(i=1; i<=m; i++){
		P[i].first = (P[i].first - s + n) % n + 1;
		P[i].second = (P[i].second - s + n) % n + 1;
		if(P[i].first >= P[i].second) P[i].second += n;
		
		if(chk[i] && ans[i] == 1) X[P[i].first].push_back(i);
		else if(!chk[i]) Y[P[i].first].push_back(i);
	}
	
	e = P[x].second; y = -1;
	
	for(i=1; i<=n; i++){
		for(int &t: X[i]) e = max(e, P[t].second);
		for(int &t: Y[i]){
			if(y == -1) y = t;
			else if(P[t].second > P[y].second) y = t;
		}
		
		if(i == e){
			if(y == -1) die();
			ans[y] = 1;
			e = P[y].second;
			y = -1;
		}
	}
	
	for(i=1; i<=m; i++) printf("%d", ans[i]);
	printf("\n");
	
	return 0;
}

Compilation message

alternating.cpp: In function 'int main()':
alternating.cpp:30:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d", &n, &m);
  ~~~~~^~~~~~~~~~~~~~~~
alternating.cpp:33:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d", &a, &b);
   ~~~~~^~~~~~~~~~~~~~~~

Subtask #1
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 11 ms 9848 KB Output is correct
2 Correct 11 ms 9924 KB Output is correct
3 Correct 10 ms 9924 KB Output is correct
4 Correct 11 ms 9924 KB Output is correct
5 Correct 11 ms 9944 KB Output is correct
6 Correct 11 ms 9988 KB Output is correct
7 Correct 11 ms 9988 KB Output is correct
8 Correct 12 ms 9988 KB Output is correct
9 Correct 11 ms 10188 KB Output is correct
10 Correct 12 ms 10188 KB Output is correct
11 Correct 11 ms 10188 KB Output is correct
12 Correct 11 ms 10188 KB Output is correct
13 Correct 11 ms 10188 KB Output is correct
14 Correct 12 ms 10188 KB Output is correct
15 Correct 12 ms 10188 KB Output is correct
16 Correct 13 ms 10188 KB Output is correct
17 Correct 12 ms 10188 KB Output is correct
18 Correct 12 ms 10196 KB Output is correct
19 Correct 13 ms 10196 KB Output is correct
20 Correct 11 ms 10196 KB Output is correct
21 Correct 11 ms 10196 KB Output is correct
22 Correct 11 ms 10196 KB Output is correct
23 Correct 14 ms 10196 KB Output is correct
24 Correct 11 ms 10196 KB Output is correct
25 Correct 12 ms 10196 KB Output is correct
26 Correct 12 ms 10196 KB Output is correct
27 Correct 12 ms 10216 KB Output is correct
28 Correct 12 ms 10216 KB Output is correct
29 Correct 12 ms 10216 KB Output is correct
30 Correct 12 ms 10216 KB Output is correct
31 Correct 12 ms 10216 KB Output is correct
32 Correct 13 ms 10216 KB Output is correct
33 Correct 12 ms 10216 KB Output is correct
34 Correct 11 ms 10216 KB Output is correct
35 Correct 14 ms 10216 KB Output is correct
36 Correct 13 ms 10216 KB Output is correct
37 Correct 12 ms 10216 KB Output is correct
38 Correct 13 ms 10216 KB Output is correct
39 Correct 14 ms 10216 KB Output is correct
40 Correct 13 ms 10216 KB Output is correct

Subtask #2
0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 11 ms 9848 KB Output is correct
2 Correct 11 ms 9924 KB Output is correct
3 Correct 10 ms 9924 KB Output is correct
4 Correct 11 ms 9924 KB Output is correct
5 Correct 11 ms 9944 KB Output is correct
6 Correct 11 ms 9988 KB Output is correct
7 Correct 11 ms 9988 KB Output is correct
8 Correct 12 ms 9988 KB Output is correct
9 Correct 11 ms 10188 KB Output is correct
10 Correct 12 ms 10188 KB Output is correct
11 Correct 11 ms 10188 KB Output is correct
12 Correct 11 ms 10188 KB Output is correct
13 Correct 11 ms 10188 KB Output is correct
14 Correct 12 ms 10188 KB Output is correct
15 Correct 12 ms 10188 KB Output is correct
16 Correct 13 ms 10188 KB Output is correct
17 Correct 12 ms 10188 KB Output is correct
18 Correct 12 ms 10196 KB Output is correct
19 Correct 13 ms 10196 KB Output is correct
20 Correct 11 ms 10196 KB Output is correct
21 Correct 11 ms 10196 KB Output is correct
22 Correct 11 ms 10196 KB Output is correct
23 Correct 14 ms 10196 KB Output is correct
24 Correct 11 ms 10196 KB Output is correct
25 Correct 12 ms 10196 KB Output is correct
26 Correct 12 ms 10196 KB Output is correct
27 Correct 12 ms 10216 KB Output is correct
28 Correct 12 ms 10216 KB Output is correct
29 Correct 12 ms 10216 KB Output is correct
30 Correct 12 ms 10216 KB Output is correct
31 Correct 12 ms 10216 KB Output is correct
32 Correct 13 ms 10216 KB Output is correct
33 Correct 12 ms 10216 KB Output is correct
34 Correct 11 ms 10216 KB Output is correct
35 Correct 14 ms 10216 KB Output is correct
36 Correct 13 ms 10216 KB Output is correct
37 Correct 12 ms 10216 KB Output is correct
38 Correct 13 ms 10216 KB Output is correct
39 Correct 14 ms 10216 KB Output is correct
40 Correct 13 ms 10216 KB Output is correct
41 Correct 11 ms 10216 KB Output is correct
42 Correct 14 ms 10216 KB Output is correct
43 Correct 12 ms 10216 KB Output is correct
44 Correct 11 ms 10216 KB Output is correct
45 Correct 11 ms 10216 KB Output is correct
46 Correct 11 ms 10216 KB Output is correct
47 Correct 13 ms 10216 KB Output is correct
48 Correct 13 ms 10216 KB Output is correct
49 Correct 13 ms 10216 KB Output is correct
50 Correct 11 ms 10216 KB Output is correct
51 Correct 13 ms 10216 KB Output is correct
52 Correct 10 ms 10216 KB Output is correct
53 Correct 12 ms 10216 KB Output is correct
54 Correct 11 ms 10216 KB Output is correct
55 Correct 11 ms 10216 KB Output is correct
56 Correct 11 ms 10216 KB Output is correct
57 Correct 11 ms 10216 KB Output is correct
58 Correct 11 ms 10216 KB Output is correct
59 Correct 14 ms 10216 KB Output is correct
60 Correct 11 ms 10216 KB Output is correct
61 Correct 12 ms 10216 KB Output is correct
62 Incorrect 11 ms 10216 KB no wires in direction 0 between segments 59 and 59
63 Halted 0 ms 0 KB -

Subtask #3
0 / 22.0

# Verdict Execution time Memory Grader output
1 Correct 11 ms 9848 KB Output is correct
2 Correct 11 ms 9924 KB Output is correct
3 Correct 10 ms 9924 KB Output is correct
4 Correct 11 ms 9924 KB Output is correct
5 Correct 11 ms 9944 KB Output is correct
6 Correct 11 ms 9988 KB Output is correct
7 Correct 11 ms 9988 KB Output is correct
8 Correct 12 ms 9988 KB Output is correct
9 Correct 11 ms 10188 KB Output is correct
10 Correct 12 ms 10188 KB Output is correct
11 Correct 11 ms 10188 KB Output is correct
12 Correct 11 ms 10188 KB Output is correct
13 Correct 11 ms 10188 KB Output is correct
14 Correct 12 ms 10188 KB Output is correct
15 Correct 12 ms 10188 KB Output is correct
16 Correct 13 ms 10188 KB Output is correct
17 Correct 12 ms 10188 KB Output is correct
18 Correct 12 ms 10196 KB Output is correct
19 Correct 13 ms 10196 KB Output is correct
20 Correct 11 ms 10196 KB Output is correct
21 Correct 11 ms 10196 KB Output is correct
22 Correct 11 ms 10196 KB Output is correct
23 Correct 14 ms 10196 KB Output is correct
24 Correct 11 ms 10196 KB Output is correct
25 Correct 12 ms 10196 KB Output is correct
26 Correct 12 ms 10196 KB Output is correct
27 Correct 12 ms 10216 KB Output is correct
28 Correct 12 ms 10216 KB Output is correct
29 Correct 12 ms 10216 KB Output is correct
30 Correct 12 ms 10216 KB Output is correct
31 Correct 12 ms 10216 KB Output is correct
32 Correct 13 ms 10216 KB Output is correct
33 Correct 12 ms 10216 KB Output is correct
34 Correct 11 ms 10216 KB Output is correct
35 Correct 14 ms 10216 KB Output is correct
36 Correct 13 ms 10216 KB Output is correct
37 Correct 12 ms 10216 KB Output is correct
38 Correct 13 ms 10216 KB Output is correct
39 Correct 14 ms 10216 KB Output is correct
40 Correct 13 ms 10216 KB Output is correct
41 Correct 11 ms 10216 KB Output is correct
42 Correct 14 ms 10216 KB Output is correct
43 Correct 12 ms 10216 KB Output is correct
44 Correct 11 ms 10216 KB Output is correct
45 Correct 11 ms 10216 KB Output is correct
46 Correct 11 ms 10216 KB Output is correct
47 Correct 13 ms 10216 KB Output is correct
48 Correct 13 ms 10216 KB Output is correct
49 Correct 13 ms 10216 KB Output is correct
50 Correct 11 ms 10216 KB Output is correct
51 Correct 13 ms 10216 KB Output is correct
52 Correct 10 ms 10216 KB Output is correct
53 Correct 12 ms 10216 KB Output is correct
54 Correct 11 ms 10216 KB Output is correct
55 Correct 11 ms 10216 KB Output is correct
56 Correct 11 ms 10216 KB Output is correct
57 Correct 11 ms 10216 KB Output is correct
58 Correct 11 ms 10216 KB Output is correct
59 Correct 14 ms 10216 KB Output is correct
60 Correct 11 ms 10216 KB Output is correct
61 Correct 12 ms 10216 KB Output is correct
62 Incorrect 11 ms 10216 KB no wires in direction 0 between segments 59 and 59
63 Halted 0 ms 0 KB -

Subtask #4
0 / 19.0

# Verdict Execution time Memory Grader output
1 Correct 132 ms 17680 KB Output is correct
2 Correct 16 ms 17680 KB Output is correct
3 Correct 37 ms 17680 KB Output is correct
4 Correct 74 ms 17680 KB Output is correct
5 Correct 174 ms 18456 KB Output is correct
6 Correct 87 ms 18456 KB Output is correct
7 Correct 154 ms 18456 KB Output is correct
8 Correct 19 ms 18456 KB Output is correct
9 Correct 16 ms 18456 KB Output is correct
10 Correct 164 ms 18784 KB Output is correct
11 Correct 150 ms 18784 KB Output is correct
12 Correct 132 ms 18784 KB Output is correct
13 Incorrect 15 ms 18784 KB no wires in direction 0 between segments 100000 and 100000
14 Halted 0 ms 0 KB -

Subtask #5
0 / 26.0

# Verdict Execution time Memory Grader output
1 Correct 11 ms 9848 KB Output is correct
2 Correct 11 ms 9924 KB Output is correct
3 Correct 10 ms 9924 KB Output is correct
4 Correct 11 ms 9924 KB Output is correct
5 Correct 11 ms 9944 KB Output is correct
6 Correct 11 ms 9988 KB Output is correct
7 Correct 11 ms 9988 KB Output is correct
8 Correct 12 ms 9988 KB Output is correct
9 Correct 11 ms 10188 KB Output is correct
10 Correct 12 ms 10188 KB Output is correct
11 Correct 11 ms 10188 KB Output is correct
12 Correct 11 ms 10188 KB Output is correct
13 Correct 11 ms 10188 KB Output is correct
14 Correct 12 ms 10188 KB Output is correct
15 Correct 12 ms 10188 KB Output is correct
16 Correct 13 ms 10188 KB Output is correct
17 Correct 12 ms 10188 KB Output is correct
18 Correct 12 ms 10196 KB Output is correct
19 Correct 13 ms 10196 KB Output is correct
20 Correct 11 ms 10196 KB Output is correct
21 Correct 11 ms 10196 KB Output is correct
22 Correct 11 ms 10196 KB Output is correct
23 Correct 14 ms 10196 KB Output is correct
24 Correct 11 ms 10196 KB Output is correct
25 Correct 12 ms 10196 KB Output is correct
26 Correct 12 ms 10196 KB Output is correct
27 Correct 12 ms 10216 KB Output is correct
28 Correct 12 ms 10216 KB Output is correct
29 Correct 12 ms 10216 KB Output is correct
30 Correct 12 ms 10216 KB Output is correct
31 Correct 12 ms 10216 KB Output is correct
32 Correct 13 ms 10216 KB Output is correct
33 Correct 12 ms 10216 KB Output is correct
34 Correct 11 ms 10216 KB Output is correct
35 Correct 14 ms 10216 KB Output is correct
36 Correct 13 ms 10216 KB Output is correct
37 Correct 12 ms 10216 KB Output is correct
38 Correct 13 ms 10216 KB Output is correct
39 Correct 14 ms 10216 KB Output is correct
40 Correct 13 ms 10216 KB Output is correct
41 Correct 11 ms 10216 KB Output is correct
42 Correct 14 ms 10216 KB Output is correct
43 Correct 12 ms 10216 KB Output is correct
44 Correct 11 ms 10216 KB Output is correct
45 Correct 11 ms 10216 KB Output is correct
46 Correct 11 ms 10216 KB Output is correct
47 Correct 13 ms 10216 KB Output is correct
48 Correct 13 ms 10216 KB Output is correct
49 Correct 13 ms 10216 KB Output is correct
50 Correct 11 ms 10216 KB Output is correct
51 Correct 13 ms 10216 KB Output is correct
52 Correct 10 ms 10216 KB Output is correct
53 Correct 12 ms 10216 KB Output is correct
54 Correct 11 ms 10216 KB Output is correct
55 Correct 11 ms 10216 KB Output is correct
56 Correct 11 ms 10216 KB Output is correct
57 Correct 11 ms 10216 KB Output is correct
58 Correct 11 ms 10216 KB Output is correct
59 Correct 14 ms 10216 KB Output is correct
60 Correct 11 ms 10216 KB Output is correct
61 Correct 12 ms 10216 KB Output is correct
62 Incorrect 11 ms 10216 KB no wires in direction 0 between segments 59 and 59
63 Halted 0 ms 0 KB -