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Submission #63216

# Submission time Handle Problem Language Result Execution time Memory
63216 2018-08-01T06:10:07 Z 김세빈(#1833) Alternating Current (BOI18_alternating) C++11
0 / 100
 3000 ms 18536 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[P[i].first].push_back(i);
				x = i;
			}
		}
		else Y[P[i].first].push_back(i);
	}
	
	ans[x] = 1; y = -1;
	s = P[x].first, e = P[x].second;
	
	if(s != e){
		for(i=s; ; ){
			for(int &t: X[i]){
				if(P[t].first < P[t].second){
					if(i <= e && e < P[t].second) e = P[t].second;
				}
				else{
					if(i <= e) e = P[t].second;
					else if(e < P[t].second) e = P[t].second;
				}
			}
			for(int &t: Y[i]){
				if(y == -1) y = t;
				else if(P[t].first < P[t].second){
					if(i <= P[y].second && P[y].second < P[t].second) y = t;
				}
				else{
					if(i <= P[y].second) y = t;
					else if(P[y].second < P[t].second) y = t;
				}
			}
			
			if(i == e){
				if(y == -1) die();
				ans[y] = 1;
				if(P[y].first == P[y].second) break;
				e = P[y].second;
				i = P[y].first;
				y = -1;
			}
			else{
				i ++; if(i > n) i -= n;
			}
			
			if(i == s) break;
		}
	}
	
	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
0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 11 ms 9848 KB Output is correct
2 Correct 10 ms 9960 KB Output is correct
3 Correct 11 ms 9960 KB Output is correct
4 Correct 13 ms 9960 KB Output is correct
5 Correct 12 ms 9976 KB Output is correct
6 Correct 14 ms 10020 KB Output is correct
7 Correct 15 ms 10020 KB Output is correct
8 Correct 13 ms 10044 KB Output is correct
9 Correct 12 ms 10044 KB Output is correct
10 Correct 17 ms 10044 KB Output is correct
11 Correct 16 ms 10044 KB Output is correct
12 Correct 13 ms 10044 KB Output is correct
13 Correct 14 ms 10044 KB Output is correct
14 Correct 13 ms 10172 KB Output is correct
15 Correct 13 ms 10176 KB Output is correct
16 Correct 11 ms 10176 KB Output is correct
17 Correct 11 ms 10176 KB Output is correct
18 Correct 15 ms 10176 KB Output is correct
19 Correct 13 ms 10220 KB Output is correct
20 Correct 14 ms 10220 KB Output is correct
21 Correct 11 ms 10220 KB Output is correct
22 Correct 15 ms 10220 KB Output is correct
23 Correct 14 ms 10220 KB Output is correct
24 Correct 11 ms 10220 KB Output is correct
25 Correct 15 ms 10220 KB Output is correct
26 Correct 13 ms 10220 KB Output is correct
27 Correct 13 ms 10220 KB Output is correct
28 Correct 14 ms 10220 KB Output is correct
29 Correct 13 ms 10220 KB Output is correct
30 Correct 13 ms 10220 KB Output is correct
31 Correct 14 ms 10220 KB Output is correct
32 Correct 13 ms 10220 KB Output is correct
33 Correct 15 ms 10220 KB Output is correct
34 Correct 14 ms 10220 KB Output is correct
35 Correct 13 ms 10220 KB Output is correct
36 Execution timed out 3031 ms 10220 KB Time limit exceeded
37 Halted 0 ms 0 KB -

Subtask #2
0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 11 ms 9848 KB Output is correct
2 Correct 10 ms 9960 KB Output is correct
3 Correct 11 ms 9960 KB Output is correct
4 Correct 13 ms 9960 KB Output is correct
5 Correct 12 ms 9976 KB Output is correct
6 Correct 14 ms 10020 KB Output is correct
7 Correct 15 ms 10020 KB Output is correct
8 Correct 13 ms 10044 KB Output is correct
9 Correct 12 ms 10044 KB Output is correct
10 Correct 17 ms 10044 KB Output is correct
11 Correct 16 ms 10044 KB Output is correct
12 Correct 13 ms 10044 KB Output is correct
13 Correct 14 ms 10044 KB Output is correct
14 Correct 13 ms 10172 KB Output is correct
15 Correct 13 ms 10176 KB Output is correct
16 Correct 11 ms 10176 KB Output is correct
17 Correct 11 ms 10176 KB Output is correct
18 Correct 15 ms 10176 KB Output is correct
19 Correct 13 ms 10220 KB Output is correct
20 Correct 14 ms 10220 KB Output is correct
21 Correct 11 ms 10220 KB Output is correct
22 Correct 15 ms 10220 KB Output is correct
23 Correct 14 ms 10220 KB Output is correct
24 Correct 11 ms 10220 KB Output is correct
25 Correct 15 ms 10220 KB Output is correct
26 Correct 13 ms 10220 KB Output is correct
27 Correct 13 ms 10220 KB Output is correct
28 Correct 14 ms 10220 KB Output is correct
29 Correct 13 ms 10220 KB Output is correct
30 Correct 13 ms 10220 KB Output is correct
31 Correct 14 ms 10220 KB Output is correct
32 Correct 13 ms 10220 KB Output is correct
33 Correct 15 ms 10220 KB Output is correct
34 Correct 14 ms 10220 KB Output is correct
35 Correct 13 ms 10220 KB Output is correct
36 Execution timed out 3031 ms 10220 KB Time limit exceeded
37 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 10 ms 9960 KB Output is correct
3 Correct 11 ms 9960 KB Output is correct
4 Correct 13 ms 9960 KB Output is correct
5 Correct 12 ms 9976 KB Output is correct
6 Correct 14 ms 10020 KB Output is correct
7 Correct 15 ms 10020 KB Output is correct
8 Correct 13 ms 10044 KB Output is correct
9 Correct 12 ms 10044 KB Output is correct
10 Correct 17 ms 10044 KB Output is correct
11 Correct 16 ms 10044 KB Output is correct
12 Correct 13 ms 10044 KB Output is correct
13 Correct 14 ms 10044 KB Output is correct
14 Correct 13 ms 10172 KB Output is correct
15 Correct 13 ms 10176 KB Output is correct
16 Correct 11 ms 10176 KB Output is correct
17 Correct 11 ms 10176 KB Output is correct
18 Correct 15 ms 10176 KB Output is correct
19 Correct 13 ms 10220 KB Output is correct
20 Correct 14 ms 10220 KB Output is correct
21 Correct 11 ms 10220 KB Output is correct
22 Correct 15 ms 10220 KB Output is correct
23 Correct 14 ms 10220 KB Output is correct
24 Correct 11 ms 10220 KB Output is correct
25 Correct 15 ms 10220 KB Output is correct
26 Correct 13 ms 10220 KB Output is correct
27 Correct 13 ms 10220 KB Output is correct
28 Correct 14 ms 10220 KB Output is correct
29 Correct 13 ms 10220 KB Output is correct
30 Correct 13 ms 10220 KB Output is correct
31 Correct 14 ms 10220 KB Output is correct
32 Correct 13 ms 10220 KB Output is correct
33 Correct 15 ms 10220 KB Output is correct
34 Correct 14 ms 10220 KB Output is correct
35 Correct 13 ms 10220 KB Output is correct
36 Execution timed out 3031 ms 10220 KB Time limit exceeded
37 Halted 0 ms 0 KB -

Subtask #4
0 / 19.0

# Verdict Execution time Memory Grader output
1 Correct 163 ms 17776 KB Output is correct
2 Correct 15 ms 17776 KB Output is correct
3 Correct 40 ms 17776 KB Output is correct
4 Correct 68 ms 17776 KB Output is correct
5 Correct 251 ms 18536 KB Output is correct
6 Correct 122 ms 18536 KB Output is correct
7 Execution timed out 3045 ms 18536 KB Time limit exceeded
8 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 10 ms 9960 KB Output is correct
3 Correct 11 ms 9960 KB Output is correct
4 Correct 13 ms 9960 KB Output is correct
5 Correct 12 ms 9976 KB Output is correct
6 Correct 14 ms 10020 KB Output is correct
7 Correct 15 ms 10020 KB Output is correct
8 Correct 13 ms 10044 KB Output is correct
9 Correct 12 ms 10044 KB Output is correct
10 Correct 17 ms 10044 KB Output is correct
11 Correct 16 ms 10044 KB Output is correct
12 Correct 13 ms 10044 KB Output is correct
13 Correct 14 ms 10044 KB Output is correct
14 Correct 13 ms 10172 KB Output is correct
15 Correct 13 ms 10176 KB Output is correct
16 Correct 11 ms 10176 KB Output is correct
17 Correct 11 ms 10176 KB Output is correct
18 Correct 15 ms 10176 KB Output is correct
19 Correct 13 ms 10220 KB Output is correct
20 Correct 14 ms 10220 KB Output is correct
21 Correct 11 ms 10220 KB Output is correct
22 Correct 15 ms 10220 KB Output is correct
23 Correct 14 ms 10220 KB Output is correct
24 Correct 11 ms 10220 KB Output is correct
25 Correct 15 ms 10220 KB Output is correct
26 Correct 13 ms 10220 KB Output is correct
27 Correct 13 ms 10220 KB Output is correct
28 Correct 14 ms 10220 KB Output is correct
29 Correct 13 ms 10220 KB Output is correct
30 Correct 13 ms 10220 KB Output is correct
31 Correct 14 ms 10220 KB Output is correct
32 Correct 13 ms 10220 KB Output is correct
33 Correct 15 ms 10220 KB Output is correct
34 Correct 14 ms 10220 KB Output is correct
35 Correct 13 ms 10220 KB Output is correct
36 Execution timed out 3031 ms 10220 KB Time limit exceeded
37 Halted 0 ms 0 KB -