Submission #63253

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
63253	2018-08-01T07:06:28 Z	김세빈(#1833)	Alternating Current (BOI18_alternating)	C++11	33 / 100	224 ms	18444 KB

alternating

#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 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, j, 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);
	}
	
	s = 1; e = P[x].second; y = -1;
	
	for(i=1; i<=n; i++){
		for(int &t: X[i]) e = max(e, P[t].second);
		
		if(i == e){
			y = -1;
			for(j=s; j<=e; j++){
				for(int &t: Y[j]){
					if(P[t].second > e) y = t;
				}
			}
			if(y == -1) die();
			
			ans[y] = 1;
			e = P[y].second;
			s = i = P[y].first;
			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:29:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d", &n, &m);
  ~~~~~^~~~~~~~~~~~~~~~
alternating.cpp:32:8: 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	12 ms	9848 KB	Output is correct
2	Correct	12 ms	9848 KB	Output is correct
3	Correct	11 ms	10012 KB	Output is correct
4	Correct	10 ms	10012 KB	Output is correct
5	Correct	10 ms	10020 KB	Output is correct
6	Correct	12 ms	10020 KB	Output is correct
7	Correct	11 ms	10020 KB	Output is correct
8	Correct	13 ms	10020 KB	Output is correct
9	Correct	12 ms	10020 KB	Output is correct
10	Correct	11 ms	10064 KB	Output is correct
11	Correct	12 ms	10064 KB	Output is correct
12	Correct	11 ms	10168 KB	Output is correct
13	Correct	10 ms	10168 KB	Output is correct
14	Correct	13 ms	10168 KB	Output is correct
15	Correct	13 ms	10192 KB	Output is correct
16	Correct	12 ms	10192 KB	Output is correct
17	Correct	13 ms	10192 KB	Output is correct
18	Correct	13 ms	10192 KB	Output is correct
19	Correct	13 ms	10192 KB	Output is correct
20	Correct	12 ms	10192 KB	Output is correct
21	Correct	12 ms	10192 KB	Output is correct
22	Correct	13 ms	10192 KB	Output is correct
23	Correct	12 ms	10192 KB	Output is correct
24	Correct	12 ms	10200 KB	Output is correct
25	Correct	13 ms	10200 KB	Output is correct
26	Correct	14 ms	10200 KB	Output is correct
27	Correct	13 ms	10200 KB	Output is correct
28	Correct	12 ms	10200 KB	Output is correct
29	Correct	13 ms	10200 KB	Output is correct
30	Correct	13 ms	10200 KB	Output is correct
31	Correct	14 ms	10200 KB	Output is correct
32	Correct	14 ms	10200 KB	Output is correct
33	Correct	13 ms	10200 KB	Output is correct
34	Correct	11 ms	10200 KB	Output is correct
35	Correct	13 ms	10200 KB	Output is correct
36	Correct	12 ms	10200 KB	Output is correct
37	Correct	13 ms	10200 KB	Output is correct
38	Correct	13 ms	10200 KB	Output is correct
39	Correct	14 ms	10200 KB	Output is correct
40	Correct	13 ms	10200 KB	Output is correct

Subtask #2
20.0 / 20.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	12 ms	9848 KB	Output is correct
2	Correct	12 ms	9848 KB	Output is correct
3	Correct	11 ms	10012 KB	Output is correct
4	Correct	10 ms	10012 KB	Output is correct
5	Correct	10 ms	10020 KB	Output is correct
6	Correct	12 ms	10020 KB	Output is correct
7	Correct	11 ms	10020 KB	Output is correct
8	Correct	13 ms	10020 KB	Output is correct
9	Correct	12 ms	10020 KB	Output is correct
10	Correct	11 ms	10064 KB	Output is correct
11	Correct	12 ms	10064 KB	Output is correct
12	Correct	11 ms	10168 KB	Output is correct
13	Correct	10 ms	10168 KB	Output is correct
14	Correct	13 ms	10168 KB	Output is correct
15	Correct	13 ms	10192 KB	Output is correct
16	Correct	12 ms	10192 KB	Output is correct
17	Correct	13 ms	10192 KB	Output is correct
18	Correct	13 ms	10192 KB	Output is correct
19	Correct	13 ms	10192 KB	Output is correct
20	Correct	12 ms	10192 KB	Output is correct
21	Correct	12 ms	10192 KB	Output is correct
22	Correct	13 ms	10192 KB	Output is correct
23	Correct	12 ms	10192 KB	Output is correct
24	Correct	12 ms	10200 KB	Output is correct
25	Correct	13 ms	10200 KB	Output is correct
26	Correct	14 ms	10200 KB	Output is correct
27	Correct	13 ms	10200 KB	Output is correct
28	Correct	12 ms	10200 KB	Output is correct
29	Correct	13 ms	10200 KB	Output is correct
30	Correct	13 ms	10200 KB	Output is correct
31	Correct	14 ms	10200 KB	Output is correct
32	Correct	14 ms	10200 KB	Output is correct
33	Correct	13 ms	10200 KB	Output is correct
34	Correct	11 ms	10200 KB	Output is correct
35	Correct	13 ms	10200 KB	Output is correct
36	Correct	12 ms	10200 KB	Output is correct
37	Correct	13 ms	10200 KB	Output is correct
38	Correct	13 ms	10200 KB	Output is correct
39	Correct	14 ms	10200 KB	Output is correct
40	Correct	13 ms	10200 KB	Output is correct
41	Correct	12 ms	10200 KB	Output is correct
42	Correct	13 ms	10200 KB	Output is correct
43	Correct	13 ms	10200 KB	Output is correct
44	Correct	13 ms	10200 KB	Output is correct
45	Correct	12 ms	10200 KB	Output is correct
46	Correct	14 ms	10200 KB	Output is correct
47	Correct	13 ms	10200 KB	Output is correct
48	Correct	15 ms	10200 KB	Output is correct
49	Correct	13 ms	10200 KB	Output is correct
50	Correct	13 ms	10200 KB	Output is correct
51	Correct	13 ms	10200 KB	Output is correct
52	Correct	13 ms	10200 KB	Output is correct
53	Correct	12 ms	10200 KB	Output is correct
54	Correct	14 ms	10200 KB	Output is correct
55	Correct	13 ms	10200 KB	Output is correct
56	Correct	12 ms	10200 KB	Output is correct
57	Correct	14 ms	10200 KB	Output is correct
58	Correct	13 ms	10200 KB	Output is correct
59	Correct	14 ms	10200 KB	Output is correct
60	Correct	14 ms	10200 KB	Output is correct
61	Correct	13 ms	10200 KB	Output is correct
62	Correct	13 ms	10200 KB	Output is correct
63	Correct	13 ms	10200 KB	Output is correct
64	Correct	15 ms	10200 KB	Output is correct
65	Correct	13 ms	10200 KB	Output is correct
66	Correct	13 ms	10200 KB	Output is correct
67	Correct	14 ms	10200 KB	Output is correct
68	Correct	14 ms	10200 KB	Output is correct
69	Correct	12 ms	10200 KB	Output is correct

Subtask #3
0 / 22.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	12 ms	9848 KB	Output is correct
2	Correct	12 ms	9848 KB	Output is correct
3	Correct	11 ms	10012 KB	Output is correct
4	Correct	10 ms	10012 KB	Output is correct
5	Correct	10 ms	10020 KB	Output is correct
6	Correct	12 ms	10020 KB	Output is correct
7	Correct	11 ms	10020 KB	Output is correct
8	Correct	13 ms	10020 KB	Output is correct
9	Correct	12 ms	10020 KB	Output is correct
10	Correct	11 ms	10064 KB	Output is correct
11	Correct	12 ms	10064 KB	Output is correct
12	Correct	11 ms	10168 KB	Output is correct
13	Correct	10 ms	10168 KB	Output is correct
14	Correct	13 ms	10168 KB	Output is correct
15	Correct	13 ms	10192 KB	Output is correct
16	Correct	12 ms	10192 KB	Output is correct
17	Correct	13 ms	10192 KB	Output is correct
18	Correct	13 ms	10192 KB	Output is correct
19	Correct	13 ms	10192 KB	Output is correct
20	Correct	12 ms	10192 KB	Output is correct
21	Correct	12 ms	10192 KB	Output is correct
22	Correct	13 ms	10192 KB	Output is correct
23	Correct	12 ms	10192 KB	Output is correct
24	Correct	12 ms	10200 KB	Output is correct
25	Correct	13 ms	10200 KB	Output is correct
26	Correct	14 ms	10200 KB	Output is correct
27	Correct	13 ms	10200 KB	Output is correct
28	Correct	12 ms	10200 KB	Output is correct
29	Correct	13 ms	10200 KB	Output is correct
30	Correct	13 ms	10200 KB	Output is correct
31	Correct	14 ms	10200 KB	Output is correct
32	Correct	14 ms	10200 KB	Output is correct
33	Correct	13 ms	10200 KB	Output is correct
34	Correct	11 ms	10200 KB	Output is correct
35	Correct	13 ms	10200 KB	Output is correct
36	Correct	12 ms	10200 KB	Output is correct
37	Correct	13 ms	10200 KB	Output is correct
38	Correct	13 ms	10200 KB	Output is correct
39	Correct	14 ms	10200 KB	Output is correct
40	Correct	13 ms	10200 KB	Output is correct
41	Correct	12 ms	10200 KB	Output is correct
42	Correct	13 ms	10200 KB	Output is correct
43	Correct	13 ms	10200 KB	Output is correct
44	Correct	13 ms	10200 KB	Output is correct
45	Correct	12 ms	10200 KB	Output is correct
46	Correct	14 ms	10200 KB	Output is correct
47	Correct	13 ms	10200 KB	Output is correct
48	Correct	15 ms	10200 KB	Output is correct
49	Correct	13 ms	10200 KB	Output is correct
50	Correct	13 ms	10200 KB	Output is correct
51	Correct	13 ms	10200 KB	Output is correct
52	Correct	13 ms	10200 KB	Output is correct
53	Correct	12 ms	10200 KB	Output is correct
54	Correct	14 ms	10200 KB	Output is correct
55	Correct	13 ms	10200 KB	Output is correct
56	Correct	12 ms	10200 KB	Output is correct
57	Correct	14 ms	10200 KB	Output is correct
58	Correct	13 ms	10200 KB	Output is correct
59	Correct	14 ms	10200 KB	Output is correct
60	Correct	14 ms	10200 KB	Output is correct
61	Correct	13 ms	10200 KB	Output is correct
62	Correct	13 ms	10200 KB	Output is correct
63	Correct	13 ms	10200 KB	Output is correct
64	Correct	15 ms	10200 KB	Output is correct
65	Correct	13 ms	10200 KB	Output is correct
66	Correct	13 ms	10200 KB	Output is correct
67	Correct	14 ms	10200 KB	Output is correct
68	Correct	14 ms	10200 KB	Output is correct
69	Correct	12 ms	10200 KB	Output is correct
70	Correct	13 ms	10200 KB	Output is correct
71	Correct	13 ms	10236 KB	Output is correct
72	Correct	14 ms	10236 KB	Output is correct
73	Correct	13 ms	10236 KB	Output is correct
74	Correct	14 ms	10236 KB	Output is correct
75	Correct	11 ms	10236 KB	Output is correct
76	Correct	13 ms	10236 KB	Output is correct
77	Correct	17 ms	10236 KB	Output is correct
78	Correct	12 ms	10236 KB	Output is correct
79	Correct	14 ms	10236 KB	Output is correct
80	Correct	13 ms	10236 KB	Output is correct
81	Incorrect	13 ms	10236 KB	'impossible' claimed, but there is a solution
82	Halted	0 ms	0 KB	-

Subtask #4
0 / 19.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	146 ms	17676 KB	Output is correct
2	Correct	17 ms	17676 KB	Output is correct
3	Correct	44 ms	17676 KB	Output is correct
4	Correct	76 ms	17676 KB	Output is correct
5	Correct	224 ms	18444 KB	Output is correct
6	Correct	159 ms	18444 KB	Output is correct
7	Correct	191 ms	18444 KB	Output is correct
8	Incorrect	25 ms	18444 KB	'impossible' claimed, but there is a solution
9	Halted	0 ms	0 KB	-

Subtask #5
0 / 26.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	12 ms	9848 KB	Output is correct
2	Correct	12 ms	9848 KB	Output is correct
3	Correct	11 ms	10012 KB	Output is correct
4	Correct	10 ms	10012 KB	Output is correct
5	Correct	10 ms	10020 KB	Output is correct
6	Correct	12 ms	10020 KB	Output is correct
7	Correct	11 ms	10020 KB	Output is correct
8	Correct	13 ms	10020 KB	Output is correct
9	Correct	12 ms	10020 KB	Output is correct
10	Correct	11 ms	10064 KB	Output is correct
11	Correct	12 ms	10064 KB	Output is correct
12	Correct	11 ms	10168 KB	Output is correct
13	Correct	10 ms	10168 KB	Output is correct
14	Correct	13 ms	10168 KB	Output is correct
15	Correct	13 ms	10192 KB	Output is correct
16	Correct	12 ms	10192 KB	Output is correct
17	Correct	13 ms	10192 KB	Output is correct
18	Correct	13 ms	10192 KB	Output is correct
19	Correct	13 ms	10192 KB	Output is correct
20	Correct	12 ms	10192 KB	Output is correct
21	Correct	12 ms	10192 KB	Output is correct
22	Correct	13 ms	10192 KB	Output is correct
23	Correct	12 ms	10192 KB	Output is correct
24	Correct	12 ms	10200 KB	Output is correct
25	Correct	13 ms	10200 KB	Output is correct
26	Correct	14 ms	10200 KB	Output is correct
27	Correct	13 ms	10200 KB	Output is correct
28	Correct	12 ms	10200 KB	Output is correct
29	Correct	13 ms	10200 KB	Output is correct
30	Correct	13 ms	10200 KB	Output is correct
31	Correct	14 ms	10200 KB	Output is correct
32	Correct	14 ms	10200 KB	Output is correct
33	Correct	13 ms	10200 KB	Output is correct
34	Correct	11 ms	10200 KB	Output is correct
35	Correct	13 ms	10200 KB	Output is correct
36	Correct	12 ms	10200 KB	Output is correct
37	Correct	13 ms	10200 KB	Output is correct
38	Correct	13 ms	10200 KB	Output is correct
39	Correct	14 ms	10200 KB	Output is correct
40	Correct	13 ms	10200 KB	Output is correct
41	Correct	12 ms	10200 KB	Output is correct
42	Correct	13 ms	10200 KB	Output is correct
43	Correct	13 ms	10200 KB	Output is correct
44	Correct	13 ms	10200 KB	Output is correct
45	Correct	12 ms	10200 KB	Output is correct
46	Correct	14 ms	10200 KB	Output is correct
47	Correct	13 ms	10200 KB	Output is correct
48	Correct	15 ms	10200 KB	Output is correct
49	Correct	13 ms	10200 KB	Output is correct
50	Correct	13 ms	10200 KB	Output is correct
51	Correct	13 ms	10200 KB	Output is correct
52	Correct	13 ms	10200 KB	Output is correct
53	Correct	12 ms	10200 KB	Output is correct
54	Correct	14 ms	10200 KB	Output is correct
55	Correct	13 ms	10200 KB	Output is correct
56	Correct	12 ms	10200 KB	Output is correct
57	Correct	14 ms	10200 KB	Output is correct
58	Correct	13 ms	10200 KB	Output is correct
59	Correct	14 ms	10200 KB	Output is correct
60	Correct	14 ms	10200 KB	Output is correct
61	Correct	13 ms	10200 KB	Output is correct
62	Correct	13 ms	10200 KB	Output is correct
63	Correct	13 ms	10200 KB	Output is correct
64	Correct	15 ms	10200 KB	Output is correct
65	Correct	13 ms	10200 KB	Output is correct
66	Correct	13 ms	10200 KB	Output is correct
67	Correct	14 ms	10200 KB	Output is correct
68	Correct	14 ms	10200 KB	Output is correct
69	Correct	12 ms	10200 KB	Output is correct
70	Correct	13 ms	10200 KB	Output is correct
71	Correct	13 ms	10236 KB	Output is correct
72	Correct	14 ms	10236 KB	Output is correct
73	Correct	13 ms	10236 KB	Output is correct
74	Correct	14 ms	10236 KB	Output is correct
75	Correct	11 ms	10236 KB	Output is correct
76	Correct	13 ms	10236 KB	Output is correct
77	Correct	17 ms	10236 KB	Output is correct
78	Correct	12 ms	10236 KB	Output is correct
79	Correct	14 ms	10236 KB	Output is correct
80	Correct	13 ms	10236 KB	Output is correct
81	Incorrect	13 ms	10236 KB	'impossible' claimed, but there is a solution
82	Halted	0 ms	0 KB	-

Submission #63253

Compilation message

Subtask #1 13.0 / 13.0

Subtask #2 20.0 / 20.0

Subtask #3 0 / 22.0

Subtask #4 0 / 19.0

Subtask #5 0 / 26.0

Subtask #1
13.0 / 13.0

Subtask #2
20.0 / 20.0

Subtask #3
0 / 22.0

Subtask #4
0 / 19.0

Subtask #5
0 / 26.0