Submission #307085

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
307085	2020-09-27T01:59:21 Z	Rainbowbunny	Pipes (BOI13_pipes)	C++17	100 / 100	105 ms	16872 KB

pipes

#include <bits/stdc++.h>
#define int long long
#define mp make_pair
#define eb emplace_back
#define fi first
#define se second
using namespace std;
using cd = complex <double>;
 
const long long INF = 1e15;
const int N = 3e5 + 2;
const int mod = 1e9 + 7;//998244353;//1e9 + 7;//786433;
const double Pi = acos(-1);
 
void Fastio()
{
	ios_base::sync_with_stdio(false);
	cin.tie(0);
	cout.tie(0);
}
 
int n, m;
long long a[100005], par[100005], H[100005], ans[100005];
bool Vis[100005];
long long c[2];
vector <pair <int, int> > Edge;
vector <pair <int, int> > Adj[100005];
 
void DFS(int node, int p = -1)
{
	for(auto x : Adj[node])
	{
		if(x.fi == p)
		{
			continue;
		}
		if(H[x.fi] != -1)
		{
			if((H[node] - H[x.fi]) % 2 == 1)
			{
				cout << 0;
				exit(0);
			}
		}
		else
		{
			H[x.fi] = H[node] + 1;
			DFS(x.fi, node);
		}
	}
}
 
void DFS2(int node, int p = -1)
{
	Vis[node] = true;
	for(auto x : Adj[node])
	{
		if(Vis[x.fi])
		{
			continue;
		}
		DFS2(x.fi, node);
		ans[x.se] = a[x.fi];
		a[node] -= a[x.fi]; 
	}
}
 
signed main()
{
	Fastio();
	cin >> n >> m;
	if(n < m)
	{
		cout << 0;
		return 0;
	}
	for(int i = 1; i <= n; i++)
	{
		H[i] = -1;
		cin >> a[i];
	}
	for(int i = 1; i <= m; i++)
	{
		int u, v;
		cin >> u >> v;
		Adj[u].eb(v, i - 1);
		Adj[v].eb(u, i - 1);
		Edge.eb(u, v);
	}
	H[1] = 0;
	DFS(1);
	for(int i = 1; i <= n; i++)
	{
		c[H[i] & 1] += a[i];
	}
	for(int i = 0; i < m; i++)
	{
		pair <int, int> x = Edge[i];
		if(H[x.fi] % 2 == H[x.se] % 2)
		{
			if(H[x.fi] % 2 == 1)
			{
				ans[i] = (c[1] - c[0]) / 2;
				a[x.fi] -= ans[i];
				a[x.se] -= ans[i];
			}
			else
			{
				ans[i] = (c[0] - c[1]) / 2;
				a[x.fi] -= ans[i];
				a[x.se] -= ans[i];
			}
		}
	}
	DFS2(1);
	for(int i = 0; i < m; i++)
	{
		cout << ans[i] * 2 << '\n';
	}
}

Subtask #1

30.0 / 30.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	2 ms	2688 KB	Output is correct
2	Correct	2 ms	2688 KB	Output is correct
3	Correct	2 ms	2816 KB	Output is correct
4	Correct	87 ms	12260 KB	Output is correct
5	Correct	2 ms	2688 KB	Output is correct
6	Correct	2 ms	2688 KB	Output is correct
7	Correct	2 ms	2688 KB	Output is correct
8	Correct	2 ms	2688 KB	Output is correct
9	Correct	2 ms	2816 KB	Output is correct
10	Correct	3 ms	2816 KB	Output is correct
11	Correct	3 ms	2816 KB	Output is correct
12	Correct	3 ms	2816 KB	Output is correct
13	Correct	63 ms	10340 KB	Output is correct
14	Correct	82 ms	11748 KB	Output is correct
15	Correct	99 ms	12264 KB	Output is correct
16	Correct	76 ms	10852 KB	Output is correct
17	Correct	89 ms	12260 KB	Output is correct
18	Correct	88 ms	12260 KB	Output is correct
19	Correct	103 ms	14628 KB	Output is correct
20	Correct	2 ms	2688 KB	Output is correct
21	Correct	3 ms	2816 KB	Output is correct
22	Correct	88 ms	12260 KB	Output is correct
23	Correct	67 ms	10340 KB	Output is correct
24	Correct	92 ms	12396 KB	Output is correct
25	Correct	71 ms	10728 KB	Output is correct

Subtask #2

70.0 / 70.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	2 ms	2688 KB	Output is correct
2	Correct	3 ms	2816 KB	Output is correct
3	Correct	64 ms	12644 KB	Output is correct
4	Correct	2 ms	2688 KB	Output is correct
5	Correct	2 ms	2688 KB	Output is correct
6	Correct	2 ms	2688 KB	Output is correct
7	Correct	2 ms	2688 KB	Output is correct
8	Correct	2 ms	2688 KB	Output is correct
9	Correct	2 ms	2688 KB	Output is correct
10	Correct	2 ms	2688 KB	Output is correct
11	Correct	2 ms	2688 KB	Output is correct
12	Correct	2 ms	2720 KB	Output is correct
13	Correct	2 ms	2688 KB	Output is correct
14	Correct	2 ms	2688 KB	Output is correct
15	Correct	3 ms	2816 KB	Output is correct
16	Correct	3 ms	2816 KB	Output is correct
17	Correct	2 ms	2816 KB	Output is correct
18	Correct	2 ms	2688 KB	Output is correct
19	Correct	2 ms	2688 KB	Output is correct
20	Correct	2 ms	2688 KB	Output is correct
21	Correct	2 ms	2688 KB	Output is correct
22	Correct	3 ms	2816 KB	Output is correct
23	Correct	78 ms	13028 KB	Output is correct
24	Correct	101 ms	14820 KB	Output is correct
25	Correct	64 ms	12520 KB	Output is correct
26	Correct	2 ms	2688 KB	Output is correct
27	Correct	2 ms	2688 KB	Output is correct
28	Correct	2 ms	2688 KB	Output is correct
29	Correct	2 ms	2688 KB	Output is correct
30	Correct	102 ms	16228 KB	Output is correct
31	Correct	105 ms	16356 KB	Output is correct
32	Correct	105 ms	13028 KB	Output is correct
33	Correct	66 ms	13540 KB	Output is correct
34	Correct	2 ms	2688 KB	Output is correct
35	Correct	2 ms	2688 KB	Output is correct
36	Correct	2 ms	2688 KB	Output is correct
37	Correct	2 ms	2688 KB	Output is correct
38	Correct	103 ms	15844 KB	Output is correct
39	Correct	93 ms	12644 KB	Output is correct
40	Correct	100 ms	14564 KB	Output is correct
41	Correct	79 ms	15076 KB	Output is correct
42	Correct	2 ms	2688 KB	Output is correct
43	Correct	2 ms	2688 KB	Output is correct
44	Correct	2 ms	2688 KB	Output is correct
45	Correct	2 ms	2688 KB	Output is correct
46	Correct	105 ms	16872 KB	Output is correct
47	Correct	97 ms	14692 KB	Output is correct
48	Correct	102 ms	16228 KB	Output is correct
49	Correct	60 ms	11236 KB	Output is correct
50	Correct	2 ms	2816 KB	Output is correct
51	Correct	2 ms	2688 KB	Output is correct
52	Correct	2 ms	2688 KB	Output is correct
53	Correct	2 ms	2688 KB	Output is correct
54	Correct	100 ms	15332 KB	Output is correct