Submission #477111

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
477111	2021-09-30T14:49:45 Z	Jasiekstrz	Pipes (BOI13_pipes)	C++17	100 / 100	209 ms	23092 KB

pipes

#include<bits/stdc++.h>
#define fi first
#define se second
using namespace std;
const int N=1e5,M=5e5;
int val[N+10];
vector<pair<int,int>> e[N+10];
bool vis[N+10];
bool on_c[N+10];
vector<int> stck;
int ans[M+10];
int pref[N+10];
int ss=0;
void on_cycle(int x)
{
	vis[x]=true;
	stck.push_back(x);
	for(auto v:e[x])
	{
		if(!vis[v.fi])
			on_cycle(v.fi);
		else if(!on_c[x] && stck.size()>=2 && stck[stck.size()-2]!=v.fi)
		{
			for(size_t i=stck.size()-1;stck[i]!=v.fi;i--)
				on_c[stck[i]]=true;
			on_c[v.fi]=true;
		}
	}
	stck.pop_back();
}
void solve_trees(int x,int p)
{
	for(auto v:e[x])
	{
		if(on_c[v.fi] || v.fi==p)
			continue;
		solve_trees(v.fi,x);
		ans[v.se]=2*val[v.fi];
		val[x]-=val[v.fi];
	}
	return;
}
void get_pref(int x,int p,int p0)
{
	for(auto v:e[x])
	{
		if(!on_c[v.fi] || v.fi==p || v.fi==p0)
			continue;
		pref[v.fi]=val[v.fi]-pref[x];
		get_pref(v.fi,x,p0);
		return;
	}
	ss=pref[x];
	return;
}
void solve_cycle(int x,int p,int p0,bool sgn_x) // true -> +, false -> -
{
	for(auto v:e[x])
	{
		if(!on_c[v.fi] || v.fi==p)
			continue;
		if(v.fi==p0)
		{
			ans[v.se]=ss;
			return;
		}
		if(sgn_x)
			ans[v.se]=-ss+2*pref[x];
		else
			ans[v.se]=ss+2*pref[x];
		solve_cycle(v.fi,x,p0,!sgn_x);
		return;
	}
	return;
}
int main()
{
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	cout.tie(NULL);
	int n,m;
	cin>>n>>m;
	for(int i=1;i<=n;i++)
		cin>>val[i];
	for(int i=1;i<=m;i++)
	{
		int a,b;
		cin>>a>>b;
		e[a].emplace_back(b,i);
		e[b].emplace_back(a,i);
	}
	if(m>n)
	{
		cout<<"0\n";
		return 0;
	}
	if(m<n)
		solve_trees(1,0);
	else
	{
		on_cycle(1);
		int cnt_c=0,cc=0;
		for(int i=1;i<=n;i++)
		{
			if(on_c[i])
			{
				solve_trees(i,0);
				cnt_c++;
				cc=i;
			}
		}
		if(cnt_c%2==0)
		{
			cout<<"0\n";
			return 0;
		}
		pref[cc]=val[cc];
		get_pref(cc,0,cc);
		solve_cycle(cc,0,cc,true);
	}
	for(int i=1;i<=m;i++)
		cout<<ans[i]<<"\n";
	return 0;
}

Subtask #1

30.0 / 30.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	2 ms	2636 KB	Output is correct
2	Correct	2 ms	2636 KB	Output is correct
3	Correct	2 ms	2636 KB	Output is correct
4	Correct	62 ms	9176 KB	Output is correct
5	Correct	2 ms	2636 KB	Output is correct
6	Correct	2 ms	2684 KB	Output is correct
7	Correct	2 ms	2636 KB	Output is correct
8	Correct	3 ms	2636 KB	Output is correct
9	Correct	2 ms	2636 KB	Output is correct
10	Correct	2 ms	2636 KB	Output is correct
11	Correct	2 ms	2636 KB	Output is correct
12	Correct	2 ms	2688 KB	Output is correct
13	Correct	53 ms	7820 KB	Output is correct
14	Correct	87 ms	8776 KB	Output is correct
15	Correct	72 ms	9100 KB	Output is correct
16	Correct	60 ms	8140 KB	Output is correct
17	Correct	71 ms	9156 KB	Output is correct
18	Correct	62 ms	9156 KB	Output is correct
19	Correct	75 ms	12412 KB	Output is correct
20	Correct	2 ms	2668 KB	Output is correct
21	Correct	3 ms	2636 KB	Output is correct
22	Correct	66 ms	9144 KB	Output is correct
23	Correct	51 ms	7748 KB	Output is correct
24	Correct	64 ms	9124 KB	Output is correct
25	Correct	55 ms	8080 KB	Output is correct

Subtask #2

70.0 / 70.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	2 ms	2636 KB	Output is correct
2	Correct	2 ms	2764 KB	Output is correct
3	Correct	74 ms	11368 KB	Output is correct
4	Correct	47 ms	7792 KB	Output is correct
5	Correct	46 ms	8060 KB	Output is correct
6	Correct	179 ms	23036 KB	Output is correct
7	Correct	2 ms	2636 KB	Output is correct
8	Correct	2 ms	2636 KB	Output is correct
9	Correct	2 ms	2636 KB	Output is correct
10	Correct	2 ms	2636 KB	Output is correct
11	Correct	2 ms	2636 KB	Output is correct
12	Correct	3 ms	2688 KB	Output is correct
13	Correct	2 ms	2680 KB	Output is correct
14	Correct	2 ms	2636 KB	Output is correct
15	Correct	2 ms	2764 KB	Output is correct
16	Correct	2 ms	2764 KB	Output is correct
17	Correct	2 ms	2696 KB	Output is correct
18	Correct	2 ms	2636 KB	Output is correct
19	Correct	2 ms	2636 KB	Output is correct
20	Correct	2 ms	2636 KB	Output is correct
21	Correct	3 ms	2764 KB	Output is correct
22	Correct	3 ms	2764 KB	Output is correct
23	Correct	57 ms	11712 KB	Output is correct
24	Correct	72 ms	13000 KB	Output is correct
25	Correct	65 ms	11348 KB	Output is correct
26	Correct	42 ms	7924 KB	Output is correct
27	Correct	50 ms	7752 KB	Output is correct
28	Correct	47 ms	8260 KB	Output is correct
29	Correct	154 ms	19324 KB	Output is correct
30	Correct	77 ms	14960 KB	Output is correct
31	Correct	92 ms	15092 KB	Output is correct
32	Correct	82 ms	10820 KB	Output is correct
33	Correct	66 ms	12352 KB	Output is correct
34	Correct	46 ms	7844 KB	Output is correct
35	Correct	47 ms	7852 KB	Output is correct
36	Correct	47 ms	8148 KB	Output is correct
37	Correct	209 ms	23092 KB	Output is correct
38	Correct	77 ms	14272 KB	Output is correct
39	Correct	65 ms	10364 KB	Output is correct
40	Correct	74 ms	12816 KB	Output is correct
41	Correct	62 ms	14268 KB	Output is correct
42	Correct	46 ms	7752 KB	Output is correct
43	Correct	42 ms	7676 KB	Output is correct
44	Correct	43 ms	8024 KB	Output is correct
45	Correct	155 ms	20408 KB	Output is correct
46	Correct	77 ms	15676 KB	Output is correct
47	Correct	78 ms	12868 KB	Output is correct
48	Correct	83 ms	14908 KB	Output is correct
49	Correct	53 ms	9540 KB	Output is correct
50	Correct	51 ms	7892 KB	Output is correct
51	Correct	47 ms	8056 KB	Output is correct
52	Correct	46 ms	7768 KB	Output is correct
53	Correct	166 ms	20420 KB	Output is correct
54	Correct	78 ms	13800 KB	Output is correct