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Submission #63252

# Submission time Handle Problem Language Result Execution time Memory
63252 2018-08-01T07:05:27 Z 김세빈(#1833) Alternating Current (BOI18_alternating) C++11
33 / 100
 197 ms 18444 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 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 = 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 11 ms 9720 KB Output is correct
2 Correct 15 ms 9856 KB Output is correct
3 Correct 12 ms 9964 KB Output is correct
4 Correct 12 ms 9964 KB Output is correct
5 Correct 12 ms 9964 KB Output is correct
6 Correct 12 ms 10072 KB Output is correct
7 Correct 11 ms 10088 KB Output is correct
8 Correct 12 ms 10216 KB Output is correct
9 Correct 9 ms 10216 KB Output is correct
10 Correct 10 ms 10216 KB Output is correct
11 Correct 12 ms 10216 KB Output is correct
12 Correct 10 ms 10216 KB Output is correct
13 Correct 10 ms 10216 KB Output is correct
14 Correct 12 ms 10216 KB Output is correct
15 Correct 11 ms 10216 KB Output is correct
16 Correct 15 ms 10216 KB Output is correct
17 Correct 13 ms 10216 KB Output is correct
18 Correct 13 ms 10216 KB Output is correct
19 Correct 12 ms 10216 KB Output is correct
20 Correct 14 ms 10216 KB Output is correct
21 Correct 13 ms 10216 KB Output is correct
22 Correct 12 ms 10216 KB Output is correct
23 Correct 12 ms 10216 KB Output is correct
24 Correct 12 ms 10216 KB Output is correct
25 Correct 11 ms 10216 KB Output is correct
26 Correct 13 ms 10216 KB Output is correct
27 Correct 10 ms 10216 KB Output is correct
28 Correct 10 ms 10216 KB Output is correct
29 Correct 13 ms 10216 KB Output is correct
30 Correct 10 ms 10216 KB Output is correct
31 Correct 10 ms 10216 KB Output is correct
32 Correct 14 ms 10216 KB Output is correct
33 Correct 10 ms 10216 KB Output is correct
34 Correct 10 ms 10216 KB Output is correct
35 Correct 13 ms 10216 KB Output is correct
36 Correct 11 ms 10216 KB Output is correct
37 Correct 13 ms 10216 KB Output is correct
38 Correct 10 ms 10216 KB Output is correct
39 Correct 10 ms 10220 KB Output is correct
40 Correct 11 ms 10220 KB Output is correct

Subtask #2
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 11 ms 9720 KB Output is correct
2 Correct 15 ms 9856 KB Output is correct
3 Correct 12 ms 9964 KB Output is correct
4 Correct 12 ms 9964 KB Output is correct
5 Correct 12 ms 9964 KB Output is correct
6 Correct 12 ms 10072 KB Output is correct
7 Correct 11 ms 10088 KB Output is correct
8 Correct 12 ms 10216 KB Output is correct
9 Correct 9 ms 10216 KB Output is correct
10 Correct 10 ms 10216 KB Output is correct
11 Correct 12 ms 10216 KB Output is correct
12 Correct 10 ms 10216 KB Output is correct
13 Correct 10 ms 10216 KB Output is correct
14 Correct 12 ms 10216 KB Output is correct
15 Correct 11 ms 10216 KB Output is correct
16 Correct 15 ms 10216 KB Output is correct
17 Correct 13 ms 10216 KB Output is correct
18 Correct 13 ms 10216 KB Output is correct
19 Correct 12 ms 10216 KB Output is correct
20 Correct 14 ms 10216 KB Output is correct
21 Correct 13 ms 10216 KB Output is correct
22 Correct 12 ms 10216 KB Output is correct
23 Correct 12 ms 10216 KB Output is correct
24 Correct 12 ms 10216 KB Output is correct
25 Correct 11 ms 10216 KB Output is correct
26 Correct 13 ms 10216 KB Output is correct
27 Correct 10 ms 10216 KB Output is correct
28 Correct 10 ms 10216 KB Output is correct
29 Correct 13 ms 10216 KB Output is correct
30 Correct 10 ms 10216 KB Output is correct
31 Correct 10 ms 10216 KB Output is correct
32 Correct 14 ms 10216 KB Output is correct
33 Correct 10 ms 10216 KB Output is correct
34 Correct 10 ms 10216 KB Output is correct
35 Correct 13 ms 10216 KB Output is correct
36 Correct 11 ms 10216 KB Output is correct
37 Correct 13 ms 10216 KB Output is correct
38 Correct 10 ms 10216 KB Output is correct
39 Correct 10 ms 10220 KB Output is correct
40 Correct 11 ms 10220 KB Output is correct
41 Correct 11 ms 10236 KB Output is correct
42 Correct 10 ms 10236 KB Output is correct
43 Correct 12 ms 10236 KB Output is correct
44 Correct 12 ms 10236 KB Output is correct
45 Correct 11 ms 10236 KB Output is correct
46 Correct 11 ms 10236 KB Output is correct
47 Correct 16 ms 10236 KB Output is correct
48 Correct 12 ms 10236 KB Output is correct
49 Correct 11 ms 10236 KB Output is correct
50 Correct 11 ms 10236 KB Output is correct
51 Correct 10 ms 10236 KB Output is correct
52 Correct 13 ms 10236 KB Output is correct
53 Correct 10 ms 10236 KB Output is correct
54 Correct 9 ms 10236 KB Output is correct
55 Correct 13 ms 10236 KB Output is correct
56 Correct 10 ms 10236 KB Output is correct
57 Correct 10 ms 10236 KB Output is correct
58 Correct 12 ms 10236 KB Output is correct
59 Correct 18 ms 10236 KB Output is correct
60 Correct 14 ms 10236 KB Output is correct
61 Correct 13 ms 10236 KB Output is correct
62 Correct 12 ms 10236 KB Output is correct
63 Correct 14 ms 10236 KB Output is correct
64 Correct 13 ms 10236 KB Output is correct
65 Correct 13 ms 10236 KB Output is correct
66 Correct 13 ms 10236 KB Output is correct
67 Correct 12 ms 10236 KB Output is correct
68 Correct 14 ms 10236 KB Output is correct
69 Correct 11 ms 10236 KB Output is correct

Subtask #3
0 / 22.0

# Verdict Execution time Memory Grader output
1 Correct 11 ms 9720 KB Output is correct
2 Correct 15 ms 9856 KB Output is correct
3 Correct 12 ms 9964 KB Output is correct
4 Correct 12 ms 9964 KB Output is correct
5 Correct 12 ms 9964 KB Output is correct
6 Correct 12 ms 10072 KB Output is correct
7 Correct 11 ms 10088 KB Output is correct
8 Correct 12 ms 10216 KB Output is correct
9 Correct 9 ms 10216 KB Output is correct
10 Correct 10 ms 10216 KB Output is correct
11 Correct 12 ms 10216 KB Output is correct
12 Correct 10 ms 10216 KB Output is correct
13 Correct 10 ms 10216 KB Output is correct
14 Correct 12 ms 10216 KB Output is correct
15 Correct 11 ms 10216 KB Output is correct
16 Correct 15 ms 10216 KB Output is correct
17 Correct 13 ms 10216 KB Output is correct
18 Correct 13 ms 10216 KB Output is correct
19 Correct 12 ms 10216 KB Output is correct
20 Correct 14 ms 10216 KB Output is correct
21 Correct 13 ms 10216 KB Output is correct
22 Correct 12 ms 10216 KB Output is correct
23 Correct 12 ms 10216 KB Output is correct
24 Correct 12 ms 10216 KB Output is correct
25 Correct 11 ms 10216 KB Output is correct
26 Correct 13 ms 10216 KB Output is correct
27 Correct 10 ms 10216 KB Output is correct
28 Correct 10 ms 10216 KB Output is correct
29 Correct 13 ms 10216 KB Output is correct
30 Correct 10 ms 10216 KB Output is correct
31 Correct 10 ms 10216 KB Output is correct
32 Correct 14 ms 10216 KB Output is correct
33 Correct 10 ms 10216 KB Output is correct
34 Correct 10 ms 10216 KB Output is correct
35 Correct 13 ms 10216 KB Output is correct
36 Correct 11 ms 10216 KB Output is correct
37 Correct 13 ms 10216 KB Output is correct
38 Correct 10 ms 10216 KB Output is correct
39 Correct 10 ms 10220 KB Output is correct
40 Correct 11 ms 10220 KB Output is correct
41 Correct 11 ms 10236 KB Output is correct
42 Correct 10 ms 10236 KB Output is correct
43 Correct 12 ms 10236 KB Output is correct
44 Correct 12 ms 10236 KB Output is correct
45 Correct 11 ms 10236 KB Output is correct
46 Correct 11 ms 10236 KB Output is correct
47 Correct 16 ms 10236 KB Output is correct
48 Correct 12 ms 10236 KB Output is correct
49 Correct 11 ms 10236 KB Output is correct
50 Correct 11 ms 10236 KB Output is correct
51 Correct 10 ms 10236 KB Output is correct
52 Correct 13 ms 10236 KB Output is correct
53 Correct 10 ms 10236 KB Output is correct
54 Correct 9 ms 10236 KB Output is correct
55 Correct 13 ms 10236 KB Output is correct
56 Correct 10 ms 10236 KB Output is correct
57 Correct 10 ms 10236 KB Output is correct
58 Correct 12 ms 10236 KB Output is correct
59 Correct 18 ms 10236 KB Output is correct
60 Correct 14 ms 10236 KB Output is correct
61 Correct 13 ms 10236 KB Output is correct
62 Correct 12 ms 10236 KB Output is correct
63 Correct 14 ms 10236 KB Output is correct
64 Correct 13 ms 10236 KB Output is correct
65 Correct 13 ms 10236 KB Output is correct
66 Correct 13 ms 10236 KB Output is correct
67 Correct 12 ms 10236 KB Output is correct
68 Correct 14 ms 10236 KB Output is correct
69 Correct 11 ms 10236 KB Output is correct
70 Correct 13 ms 10236 KB Output is correct
71 Correct 13 ms 10236 KB Output is correct
72 Correct 13 ms 10236 KB Output is correct
73 Correct 12 ms 10236 KB Output is correct
74 Correct 10 ms 10236 KB Output is correct
75 Correct 10 ms 10236 KB Output is correct
76 Correct 14 ms 10236 KB Output is correct
77 Correct 13 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 12 ms 10236 KB Output is correct
81 Incorrect 10 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 113 ms 17788 KB Output is correct
2 Correct 15 ms 17788 KB Output is correct
3 Correct 28 ms 17788 KB Output is correct
4 Correct 83 ms 17788 KB Output is correct
5 Correct 197 ms 18444 KB Output is correct
6 Correct 114 ms 18444 KB Output is correct
7 Correct 145 ms 18444 KB Output is correct
8 Incorrect 16 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 11 ms 9720 KB Output is correct
2 Correct 15 ms 9856 KB Output is correct
3 Correct 12 ms 9964 KB Output is correct
4 Correct 12 ms 9964 KB Output is correct
5 Correct 12 ms 9964 KB Output is correct
6 Correct 12 ms 10072 KB Output is correct
7 Correct 11 ms 10088 KB Output is correct
8 Correct 12 ms 10216 KB Output is correct
9 Correct 9 ms 10216 KB Output is correct
10 Correct 10 ms 10216 KB Output is correct
11 Correct 12 ms 10216 KB Output is correct
12 Correct 10 ms 10216 KB Output is correct
13 Correct 10 ms 10216 KB Output is correct
14 Correct 12 ms 10216 KB Output is correct
15 Correct 11 ms 10216 KB Output is correct
16 Correct 15 ms 10216 KB Output is correct
17 Correct 13 ms 10216 KB Output is correct
18 Correct 13 ms 10216 KB Output is correct
19 Correct 12 ms 10216 KB Output is correct
20 Correct 14 ms 10216 KB Output is correct
21 Correct 13 ms 10216 KB Output is correct
22 Correct 12 ms 10216 KB Output is correct
23 Correct 12 ms 10216 KB Output is correct
24 Correct 12 ms 10216 KB Output is correct
25 Correct 11 ms 10216 KB Output is correct
26 Correct 13 ms 10216 KB Output is correct
27 Correct 10 ms 10216 KB Output is correct
28 Correct 10 ms 10216 KB Output is correct
29 Correct 13 ms 10216 KB Output is correct
30 Correct 10 ms 10216 KB Output is correct
31 Correct 10 ms 10216 KB Output is correct
32 Correct 14 ms 10216 KB Output is correct
33 Correct 10 ms 10216 KB Output is correct
34 Correct 10 ms 10216 KB Output is correct
35 Correct 13 ms 10216 KB Output is correct
36 Correct 11 ms 10216 KB Output is correct
37 Correct 13 ms 10216 KB Output is correct
38 Correct 10 ms 10216 KB Output is correct
39 Correct 10 ms 10220 KB Output is correct
40 Correct 11 ms 10220 KB Output is correct
41 Correct 11 ms 10236 KB Output is correct
42 Correct 10 ms 10236 KB Output is correct
43 Correct 12 ms 10236 KB Output is correct
44 Correct 12 ms 10236 KB Output is correct
45 Correct 11 ms 10236 KB Output is correct
46 Correct 11 ms 10236 KB Output is correct
47 Correct 16 ms 10236 KB Output is correct
48 Correct 12 ms 10236 KB Output is correct
49 Correct 11 ms 10236 KB Output is correct
50 Correct 11 ms 10236 KB Output is correct
51 Correct 10 ms 10236 KB Output is correct
52 Correct 13 ms 10236 KB Output is correct
53 Correct 10 ms 10236 KB Output is correct
54 Correct 9 ms 10236 KB Output is correct
55 Correct 13 ms 10236 KB Output is correct
56 Correct 10 ms 10236 KB Output is correct
57 Correct 10 ms 10236 KB Output is correct
58 Correct 12 ms 10236 KB Output is correct
59 Correct 18 ms 10236 KB Output is correct
60 Correct 14 ms 10236 KB Output is correct
61 Correct 13 ms 10236 KB Output is correct
62 Correct 12 ms 10236 KB Output is correct
63 Correct 14 ms 10236 KB Output is correct
64 Correct 13 ms 10236 KB Output is correct
65 Correct 13 ms 10236 KB Output is correct
66 Correct 13 ms 10236 KB Output is correct
67 Correct 12 ms 10236 KB Output is correct
68 Correct 14 ms 10236 KB Output is correct
69 Correct 11 ms 10236 KB Output is correct
70 Correct 13 ms 10236 KB Output is correct
71 Correct 13 ms 10236 KB Output is correct
72 Correct 13 ms 10236 KB Output is correct
73 Correct 12 ms 10236 KB Output is correct
74 Correct 10 ms 10236 KB Output is correct
75 Correct 10 ms 10236 KB Output is correct
76 Correct 14 ms 10236 KB Output is correct
77 Correct 13 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 12 ms 10236 KB Output is correct
81 Incorrect 10 ms 10236 KB 'impossible' claimed, but there is a solution
82 Halted 0 ms 0 KB -