oj.uz

Submission #63592

# Submission time Handle Problem Language Result Execution time Memory
63592 2018-08-02T08:40:23 Z zetapi Alternating Current (BOI18_alternating) C++14
55 / 100
 3000 ms 9580 KB 
#include <bits/stdc++.h>
using namespace std;

#define pb  push_back
#define mp  make_pair
#define int long long
#define itr ::iterator 

#define start  first
#define length second.first

typedef pair<int,int>  pii;

const int MAX=1e5;

bool cmp(const pair<int,pii> X,const pair<int,pii> Y)
{
	if(X.start==Y.start)
		return X.length>Y.length;
	return X.start<Y.start;
}

vector<pair<int,pii>> arr;
vector<int> vec,Enclosed[MAX];

int N,M,X,Y,par[MAX],mark[MAX];	
int len,cur,pre;

int root(int X)
{
	if(par[X]==X)
		return X;
	return par[X]=root(par[X]);
}

bool Subset(int X,int Y)
{
	int RelativeStart=(arr[X].start-arr[Y].start+N)%N;
	return RelativeStart+arr[X].length<=arr[Y].length;
}

void Alternate()
{
	for(int A=0;A<vec.size();A++)
		mark[arr[vec[A]].second.second]=A%2;
	for(int A=0;A<vec.size();A++)
	{
		for(auto B:Enclosed[vec[A]])
			mark[arr[B].second.second]=mark[arr[vec[A]].second.second]^1;
	}
	return ;
}

bool ok()
{
	int BIT[MAX];
	for(int A=0;A<2;A++)
	{
		for(int B=0;B<N;B++)
			BIT[B]=0;
		for(int B=0;B<M;B++)
		{
			if(mark[arr[B].second.second]!=A)
				continue;
			//cout<<"original index "<<B<<" start "<<arr[B].start<<"  length "<<arr[B].length<<"\n";
			if(arr[B].start+arr[B].length-1>=N)
			{
				BIT[0]++;
				BIT[arr[B].start]++;
				BIT[(arr[B].start+arr[B].length-1)%N+1]--;
			}
			else
			{
				BIT[arr[B].start]++;
				BIT[arr[B].start+arr[B].length]--;
			}	
		}
		for(int A=0;A<N;A++)
		{
			BIT[A+1]+=BIT[A];
			if(!BIT[A])
				return false;
		}
	}
	return true;
}

bool ok(int L,int R,int col)
{
	int Start=vec[L];
	int End=vec[R];
	int len=(End-Start+M)%M+1;
	int high=arr[Start].start;
	for(int A=0;A<len;A++)
	{
		int cur=(Start+A)%M;
		if(mark[arr[cur].second.second]!=col)
			continue;
		int now=arr[cur].start;
		if(cur<Start)
			now+=N;
		if(now>high)
			return false;
		high=max(high,now+arr[cur].length);
	}
	return true;
}

void color(int X,int C)
{
	if(C>=0)
		mark[arr[vec[X]].second.second]=C;
	for(auto A:Enclosed[vec[X]])
		mark[arr[A].second.second]=!mark[arr[vec[X]].second.second];
	return ;
}

signed main()
{
	ios_base::sync_with_stdio(false);

	cin>>N>>M;
	for(int A=0;A<M;A++)
	{
		par[A]=A;
		cin>>X>>Y;
		X--;
		Y--;
		len=(Y-X+N)%N+1;
		arr.pb(mp(X,mp(len,A)));
	}	
	sort(arr.begin(),arr.end(),cmp);
	pre=0;
	for(int A=1;A<2*M;A++)
	{
		cur=A%M;
		if(Subset(cur,pre))
			par[cur]=pre;
		else
			pre=cur;	
	}
	for(int A=0;A<M;A++)
	{
		cur=root(A);
		if(A==cur)
			vec.pb(A);
		else
			Enclosed[cur].pb(A);
	}
	if(!(vec.size()%2))
	{
		Alternate();
		if(ok())
			for(int A=0;A<M;A++)
				cout<<mark[A];
		else
			cout<<"impossible\n";
		return 0;
	}
	else
	{
		for(int A=0;A<vec.size();A++)
		{
			int a=(A+0+vec.size())%vec.size();
			int b=(A+1+vec.size())%vec.size();
			int c=(A+2+vec.size())%vec.size();
			int d=(A+3+vec.size())%vec.size();	
			color(a,1);
			color(b,0);
			color(c,0);
			color(d,1);
			if(ok(a,d,1))
			{
				for(int A=0;A<vec.size();A++)
				{
					int cur=(d+A)%vec.size();
					if(cur==a or cur==b or cur==c or cur==d)
						continue;
					mark[arr[vec[cur]].second.second]=!mark[arr[vec[(cur-1+vec.size())%vec.size()]].second.second];
				}
				for(int A=0;A<vec.size();A++)
					color(A,-1);
				if(ok())
				{
					for(int A=0;A<M;A++)
						cout<<mark[A];
					return 0;
				}
		//		else
		//			cout<<"impossible";
		//		return 0;
			}
		}
	}
	cout<<"impossible";
	return 0;
}

Compilation message

alternating.cpp: In function 'void Alternate()':
alternating.cpp:44:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int A=0;A<vec.size();A++)
              ~^~~~~~~~~~~
alternating.cpp:46:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int A=0;A<vec.size();A++)
              ~^~~~~~~~~~~
alternating.cpp: In function 'int main()':
alternating.cpp:162:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int A=0;A<vec.size();A++)
               ~^~~~~~~~~~~
alternating.cpp:174:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int A=0;A<vec.size();A++)
                 ~^~~~~~~~~~~
alternating.cpp:181:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int A=0;A<vec.size();A++)
                 ~^~~~~~~~~~~

Subtask #1
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 2680 KB Output is correct
2 Correct 4 ms 2788 KB Output is correct
3 Correct 5 ms 2788 KB Output is correct
4 Correct 5 ms 2788 KB Output is correct
5 Correct 5 ms 2820 KB Output is correct
6 Correct 4 ms 2868 KB Output is correct
7 Correct 5 ms 2868 KB Output is correct
8 Correct 5 ms 2868 KB Output is correct
9 Correct 7 ms 2888 KB Output is correct
10 Correct 5 ms 2888 KB Output is correct
11 Correct 5 ms 2900 KB Output is correct
12 Correct 5 ms 2924 KB Output is correct
13 Correct 5 ms 2924 KB Output is correct
14 Correct 4 ms 2928 KB Output is correct
15 Correct 5 ms 2928 KB Output is correct
16 Correct 5 ms 2940 KB Output is correct
17 Correct 4 ms 2940 KB Output is correct
18 Correct 5 ms 2940 KB Output is correct
19 Correct 6 ms 2940 KB Output is correct
20 Correct 5 ms 2940 KB Output is correct
21 Correct 5 ms 2944 KB Output is correct
22 Correct 5 ms 2944 KB Output is correct
23 Correct 4 ms 2944 KB Output is correct
24 Correct 5 ms 2944 KB Output is correct
25 Correct 5 ms 2944 KB Output is correct
26 Correct 4 ms 2944 KB Output is correct
27 Correct 4 ms 2944 KB Output is correct
28 Correct 5 ms 2944 KB Output is correct
29 Correct 5 ms 2944 KB Output is correct
30 Correct 5 ms 2944 KB Output is correct
31 Correct 5 ms 2944 KB Output is correct
32 Correct 5 ms 2944 KB Output is correct
33 Correct 5 ms 2944 KB Output is correct
34 Correct 5 ms 2944 KB Output is correct
35 Correct 4 ms 2944 KB Output is correct
36 Correct 4 ms 2944 KB Output is correct
37 Correct 5 ms 2968 KB Output is correct
38 Correct 5 ms 2968 KB Output is correct
39 Correct 5 ms 2968 KB Output is correct
40 Correct 6 ms 2968 KB Output is correct

Subtask #2
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 2680 KB Output is correct
2 Correct 4 ms 2788 KB Output is correct
3 Correct 5 ms 2788 KB Output is correct
4 Correct 5 ms 2788 KB Output is correct
5 Correct 5 ms 2820 KB Output is correct
6 Correct 4 ms 2868 KB Output is correct
7 Correct 5 ms 2868 KB Output is correct
8 Correct 5 ms 2868 KB Output is correct
9 Correct 7 ms 2888 KB Output is correct
10 Correct 5 ms 2888 KB Output is correct
11 Correct 5 ms 2900 KB Output is correct
12 Correct 5 ms 2924 KB Output is correct
13 Correct 5 ms 2924 KB Output is correct
14 Correct 4 ms 2928 KB Output is correct
15 Correct 5 ms 2928 KB Output is correct
16 Correct 5 ms 2940 KB Output is correct
17 Correct 4 ms 2940 KB Output is correct
18 Correct 5 ms 2940 KB Output is correct
19 Correct 6 ms 2940 KB Output is correct
20 Correct 5 ms 2940 KB Output is correct
21 Correct 5 ms 2944 KB Output is correct
22 Correct 5 ms 2944 KB Output is correct
23 Correct 4 ms 2944 KB Output is correct
24 Correct 5 ms 2944 KB Output is correct
25 Correct 5 ms 2944 KB Output is correct
26 Correct 4 ms 2944 KB Output is correct
27 Correct 4 ms 2944 KB Output is correct
28 Correct 5 ms 2944 KB Output is correct
29 Correct 5 ms 2944 KB Output is correct
30 Correct 5 ms 2944 KB Output is correct
31 Correct 5 ms 2944 KB Output is correct
32 Correct 5 ms 2944 KB Output is correct
33 Correct 5 ms 2944 KB Output is correct
34 Correct 5 ms 2944 KB Output is correct
35 Correct 4 ms 2944 KB Output is correct
36 Correct 4 ms 2944 KB Output is correct
37 Correct 5 ms 2968 KB Output is correct
38 Correct 5 ms 2968 KB Output is correct
39 Correct 5 ms 2968 KB Output is correct
40 Correct 6 ms 2968 KB Output is correct
41 Correct 5 ms 2968 KB Output is correct
42 Correct 5 ms 2968 KB Output is correct
43 Correct 5 ms 3000 KB Output is correct
44 Correct 4 ms 3000 KB Output is correct
45 Correct 5 ms 3000 KB Output is correct
46 Correct 4 ms 3000 KB Output is correct
47 Correct 4 ms 3000 KB Output is correct
48 Correct 4 ms 3000 KB Output is correct
49 Correct 6 ms 3000 KB Output is correct
50 Correct 5 ms 3000 KB Output is correct
51 Correct 6 ms 3000 KB Output is correct
52 Correct 5 ms 3008 KB Output is correct
53 Correct 5 ms 3008 KB Output is correct
54 Correct 5 ms 3008 KB Output is correct
55 Correct 5 ms 3008 KB Output is correct
56 Correct 5 ms 3008 KB Output is correct
57 Correct 6 ms 3008 KB Output is correct
58 Correct 4 ms 3008 KB Output is correct
59 Correct 5 ms 3008 KB Output is correct
60 Correct 5 ms 3008 KB Output is correct
61 Correct 4 ms 3008 KB Output is correct
62 Correct 5 ms 3064 KB Output is correct
63 Correct 5 ms 3064 KB Output is correct
64 Correct 5 ms 3064 KB Output is correct
65 Correct 5 ms 3064 KB Output is correct
66 Correct 6 ms 3064 KB Output is correct
67 Correct 6 ms 3064 KB Output is correct
68 Correct 5 ms 3064 KB Output is correct
69 Correct 4 ms 3064 KB Output is correct

Subtask #3
22.0 / 22.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 2680 KB Output is correct
2 Correct 4 ms 2788 KB Output is correct
3 Correct 5 ms 2788 KB Output is correct
4 Correct 5 ms 2788 KB Output is correct
5 Correct 5 ms 2820 KB Output is correct
6 Correct 4 ms 2868 KB Output is correct
7 Correct 5 ms 2868 KB Output is correct
8 Correct 5 ms 2868 KB Output is correct
9 Correct 7 ms 2888 KB Output is correct
10 Correct 5 ms 2888 KB Output is correct
11 Correct 5 ms 2900 KB Output is correct
12 Correct 5 ms 2924 KB Output is correct
13 Correct 5 ms 2924 KB Output is correct
14 Correct 4 ms 2928 KB Output is correct
15 Correct 5 ms 2928 KB Output is correct
16 Correct 5 ms 2940 KB Output is correct
17 Correct 4 ms 2940 KB Output is correct
18 Correct 5 ms 2940 KB Output is correct
19 Correct 6 ms 2940 KB Output is correct
20 Correct 5 ms 2940 KB Output is correct
21 Correct 5 ms 2944 KB Output is correct
22 Correct 5 ms 2944 KB Output is correct
23 Correct 4 ms 2944 KB Output is correct
24 Correct 5 ms 2944 KB Output is correct
25 Correct 5 ms 2944 KB Output is correct
26 Correct 4 ms 2944 KB Output is correct
27 Correct 4 ms 2944 KB Output is correct
28 Correct 5 ms 2944 KB Output is correct
29 Correct 5 ms 2944 KB Output is correct
30 Correct 5 ms 2944 KB Output is correct
31 Correct 5 ms 2944 KB Output is correct
32 Correct 5 ms 2944 KB Output is correct
33 Correct 5 ms 2944 KB Output is correct
34 Correct 5 ms 2944 KB Output is correct
35 Correct 4 ms 2944 KB Output is correct
36 Correct 4 ms 2944 KB Output is correct
37 Correct 5 ms 2968 KB Output is correct
38 Correct 5 ms 2968 KB Output is correct
39 Correct 5 ms 2968 KB Output is correct
40 Correct 6 ms 2968 KB Output is correct
41 Correct 5 ms 2968 KB Output is correct
42 Correct 5 ms 2968 KB Output is correct
43 Correct 5 ms 3000 KB Output is correct
44 Correct 4 ms 3000 KB Output is correct
45 Correct 5 ms 3000 KB Output is correct
46 Correct 4 ms 3000 KB Output is correct
47 Correct 4 ms 3000 KB Output is correct
48 Correct 4 ms 3000 KB Output is correct
49 Correct 6 ms 3000 KB Output is correct
50 Correct 5 ms 3000 KB Output is correct
51 Correct 6 ms 3000 KB Output is correct
52 Correct 5 ms 3008 KB Output is correct
53 Correct 5 ms 3008 KB Output is correct
54 Correct 5 ms 3008 KB Output is correct
55 Correct 5 ms 3008 KB Output is correct
56 Correct 5 ms 3008 KB Output is correct
57 Correct 6 ms 3008 KB Output is correct
58 Correct 4 ms 3008 KB Output is correct
59 Correct 5 ms 3008 KB Output is correct
60 Correct 5 ms 3008 KB Output is correct
61 Correct 4 ms 3008 KB Output is correct
62 Correct 5 ms 3064 KB Output is correct
63 Correct 5 ms 3064 KB Output is correct
64 Correct 5 ms 3064 KB Output is correct
65 Correct 5 ms 3064 KB Output is correct
66 Correct 6 ms 3064 KB Output is correct
67 Correct 6 ms 3064 KB Output is correct
68 Correct 5 ms 3064 KB Output is correct
69 Correct 4 ms 3064 KB Output is correct
70 Correct 5 ms 3068 KB Output is correct
71 Correct 5 ms 3068 KB Output is correct
72 Correct 4 ms 3068 KB Output is correct
73 Correct 4 ms 3068 KB Output is correct
74 Correct 6 ms 3068 KB Output is correct
75 Correct 4 ms 3068 KB Output is correct
76 Correct 6 ms 3068 KB Output is correct
77 Correct 6 ms 3068 KB Output is correct
78 Correct 4 ms 3068 KB Output is correct
79 Correct 5 ms 3068 KB Output is correct
80 Correct 6 ms 3072 KB Output is correct
81 Correct 5 ms 3072 KB Output is correct
82 Correct 5 ms 3072 KB Output is correct
83 Correct 5 ms 3072 KB Output is correct
84 Correct 6 ms 3072 KB Output is correct
85 Correct 5 ms 3072 KB Output is correct
86 Correct 4 ms 3072 KB Output is correct
87 Correct 6 ms 3072 KB Output is correct
88 Correct 5 ms 3072 KB Output is correct
89 Correct 17 ms 3072 KB Output is correct
90 Correct 7 ms 3072 KB Output is correct
91 Correct 5 ms 3072 KB Output is correct
92 Correct 5 ms 3072 KB Output is correct
93 Correct 6 ms 3072 KB Output is correct
94 Correct 4 ms 3072 KB Output is correct
95 Correct 5 ms 3072 KB Output is correct
96 Correct 5 ms 3072 KB Output is correct
97 Correct 5 ms 3072 KB Output is correct
98 Correct 5 ms 3072 KB Output is correct

Subtask #4
0 / 19.0

# Verdict Execution time Memory Grader output
1 Correct 59 ms 9580 KB Output is correct
2 Correct 8 ms 9580 KB Output is correct
3 Correct 35 ms 9580 KB Output is correct
4 Correct 34 ms 9580 KB Output is correct
5 Correct 77 ms 9580 KB Output is correct
6 Execution timed out 3062 ms 9580 KB Time limit exceeded
7 Halted 0 ms 0 KB -

Subtask #5
0 / 26.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 2680 KB Output is correct
2 Correct 4 ms 2788 KB Output is correct
3 Correct 5 ms 2788 KB Output is correct
4 Correct 5 ms 2788 KB Output is correct
5 Correct 5 ms 2820 KB Output is correct
6 Correct 4 ms 2868 KB Output is correct
7 Correct 5 ms 2868 KB Output is correct
8 Correct 5 ms 2868 KB Output is correct
9 Correct 7 ms 2888 KB Output is correct
10 Correct 5 ms 2888 KB Output is correct
11 Correct 5 ms 2900 KB Output is correct
12 Correct 5 ms 2924 KB Output is correct
13 Correct 5 ms 2924 KB Output is correct
14 Correct 4 ms 2928 KB Output is correct
15 Correct 5 ms 2928 KB Output is correct
16 Correct 5 ms 2940 KB Output is correct
17 Correct 4 ms 2940 KB Output is correct
18 Correct 5 ms 2940 KB Output is correct
19 Correct 6 ms 2940 KB Output is correct
20 Correct 5 ms 2940 KB Output is correct
21 Correct 5 ms 2944 KB Output is correct
22 Correct 5 ms 2944 KB Output is correct
23 Correct 4 ms 2944 KB Output is correct
24 Correct 5 ms 2944 KB Output is correct
25 Correct 5 ms 2944 KB Output is correct
26 Correct 4 ms 2944 KB Output is correct
27 Correct 4 ms 2944 KB Output is correct
28 Correct 5 ms 2944 KB Output is correct
29 Correct 5 ms 2944 KB Output is correct
30 Correct 5 ms 2944 KB Output is correct
31 Correct 5 ms 2944 KB Output is correct
32 Correct 5 ms 2944 KB Output is correct
33 Correct 5 ms 2944 KB Output is correct
34 Correct 5 ms 2944 KB Output is correct
35 Correct 4 ms 2944 KB Output is correct
36 Correct 4 ms 2944 KB Output is correct
37 Correct 5 ms 2968 KB Output is correct
38 Correct 5 ms 2968 KB Output is correct
39 Correct 5 ms 2968 KB Output is correct
40 Correct 6 ms 2968 KB Output is correct
41 Correct 5 ms 2968 KB Output is correct
42 Correct 5 ms 2968 KB Output is correct
43 Correct 5 ms 3000 KB Output is correct
44 Correct 4 ms 3000 KB Output is correct
45 Correct 5 ms 3000 KB Output is correct
46 Correct 4 ms 3000 KB Output is correct
47 Correct 4 ms 3000 KB Output is correct
48 Correct 4 ms 3000 KB Output is correct
49 Correct 6 ms 3000 KB Output is correct
50 Correct 5 ms 3000 KB Output is correct
51 Correct 6 ms 3000 KB Output is correct
52 Correct 5 ms 3008 KB Output is correct
53 Correct 5 ms 3008 KB Output is correct
54 Correct 5 ms 3008 KB Output is correct
55 Correct 5 ms 3008 KB Output is correct
56 Correct 5 ms 3008 KB Output is correct
57 Correct 6 ms 3008 KB Output is correct
58 Correct 4 ms 3008 KB Output is correct
59 Correct 5 ms 3008 KB Output is correct
60 Correct 5 ms 3008 KB Output is correct
61 Correct 4 ms 3008 KB Output is correct
62 Correct 5 ms 3064 KB Output is correct
63 Correct 5 ms 3064 KB Output is correct
64 Correct 5 ms 3064 KB Output is correct
65 Correct 5 ms 3064 KB Output is correct
66 Correct 6 ms 3064 KB Output is correct
67 Correct 6 ms 3064 KB Output is correct
68 Correct 5 ms 3064 KB Output is correct
69 Correct 4 ms 3064 KB Output is correct
70 Correct 5 ms 3068 KB Output is correct
71 Correct 5 ms 3068 KB Output is correct
72 Correct 4 ms 3068 KB Output is correct
73 Correct 4 ms 3068 KB Output is correct
74 Correct 6 ms 3068 KB Output is correct
75 Correct 4 ms 3068 KB Output is correct
76 Correct 6 ms 3068 KB Output is correct
77 Correct 6 ms 3068 KB Output is correct
78 Correct 4 ms 3068 KB Output is correct
79 Correct 5 ms 3068 KB Output is correct
80 Correct 6 ms 3072 KB Output is correct
81 Correct 5 ms 3072 KB Output is correct
82 Correct 5 ms 3072 KB Output is correct
83 Correct 5 ms 3072 KB Output is correct
84 Correct 6 ms 3072 KB Output is correct
85 Correct 5 ms 3072 KB Output is correct
86 Correct 4 ms 3072 KB Output is correct
87 Correct 6 ms 3072 KB Output is correct
88 Correct 5 ms 3072 KB Output is correct
89 Correct 17 ms 3072 KB Output is correct
90 Correct 7 ms 3072 KB Output is correct
91 Correct 5 ms 3072 KB Output is correct
92 Correct 5 ms 3072 KB Output is correct
93 Correct 6 ms 3072 KB Output is correct
94 Correct 4 ms 3072 KB Output is correct
95 Correct 5 ms 3072 KB Output is correct
96 Correct 5 ms 3072 KB Output is correct
97 Correct 5 ms 3072 KB Output is correct
98 Correct 5 ms 3072 KB Output is correct
99 Correct 59 ms 9580 KB Output is correct
100 Correct 8 ms 9580 KB Output is correct
101 Correct 35 ms 9580 KB Output is correct
102 Correct 34 ms 9580 KB Output is correct
103 Correct 77 ms 9580 KB Output is correct
104 Execution timed out 3062 ms 9580 KB Time limit exceeded
105 Halted 0 ms 0 KB -