답안 #84111 :: oj.uz

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
84111	2018-11-13T02:51:59 Z	shoemakerjo	Pipes (BOI13_pipes)	C++14	100 / 100	262 ms	20412 KB

pipes

#include <bits/stdc++.h>

using namespace std;

#define maxn 100010
#define pii pair<int, int>
#define maxm 500010
#define ll long long

int N, M;
vector<pii> adj[maxn];
vector<pii> adj2[maxn];
ll nums[maxn];
ll ans[maxm];
int deg[maxn];
bool del[maxn];
bool vis[maxn];

void dfstree(int u, int p) {

	for (pii vp : adj[u]) {
		if (vp.first != p) {
			dfstree(vp.first, u);
			ans[vp.second] = 2 * nums[vp.first];
			nums[u] -= ans[vp.second]/2;
		}
	}

}

void gotree() {
	dfstree(1, -1);

	for (int i = 0; i < M; i++) {
		cout << ans[i] << '\n';
	}
	cout.flush();

}

int main() {
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	cin >> N >> M;
	for (int i = 1; i <= N; i++) {
		cin >> nums[i];
	}
	int u, v;
	for (int i = 0; i < M; i++) {
		cin >> u >> v;
		deg[u]++;
		deg[v]++;
		adj[u].push_back(pii(v, i));
		adj[v].push_back(pii(u, i));

	}

	if (M > N) {
		cout << 0 << endl;
		return 0;
	}
	if (M == N-1) {
		gotree();
		return 0;
	}

	stack<int> s;
	//do some stuff
	for (int i = 1; i <= N; i++) {
		if (deg[i] == 1) s.push(i);
	}
	while (s.size()) {
		u = s.top(); s.pop();
		del[u] = true;
		for (pii vp : adj[u]) {
			if (!del[vp.first]) {
				deg[vp.first]--;
				ans[vp.second] = 2*nums[u];
				nums[vp.first] -= ans[vp.second]/2;
				if (deg[vp.first] == 1) {
					del[vp.first] = true;
					s.push(vp.first);
				}
			}
		}
	}


	int cur;
	for (int i = 1; i <= N; i++) {
		if (!del[i]) {
			cur = i;
			for (pii vp : adj[i]) {
				if (!del[vp.first]) {
					adj2[i].push_back(vp);
				}
			}
		}
	}


	ll sum = 0;
	sum += nums[cur];
	ll mult = -1;
	int og = cur;
	int numseen = 1;
	// cout << "guy: " << nums[7] << endl;
	do {
		vis[cur] = true;
		// cout << "cur: " << cur << endl;

		for (int i = 1; i >= 0; i--) {
			pii vp = adj2[cur][i];
			if (!vis[vp.first]) {
				cur = vp.first;
				numseen++;
				// cout << "contribution: " << nums[cur] << " mult: " << mult << endl;
				sum += mult*nums[cur];
				mult *= -1LL;
				break;
			}
		}
	} while (!vis[cur]);

	// cout << "numseen: " << numseen << endl;
	if (numseen%2 == 0) {
		cout << 0 << endl;
		return 0;
	}

	fill(vis, vis+maxn, false);
	ans[adj2[og][0].second] = sum; //not sure if I have to divide by 2
	// cout << og << " to " << adj2[og][0].first << " assigned to " << sum << endl;
	cur = adj2[og][0].first;
	
	vis[og] = true;
	while (cur != og) {
		vis[cur] = true;
		for (int i = 0; i <= 1; i++) {
			pii vp = adj2[cur][i];
			if (!vis[vp.first]) {
				// cout << "looking at: " << cur << " to " << vp.first << endl;

				ans[vp.second] = 2 * (nums[cur] - 
					ans[adj2[cur][1-i].second]/2);
				cur = vp.first;
				// vis[cur] = true;
				break;
			}
		}
		if (vis[cur]) break;
	}

	for (int i = 0; i <= 1; i++) {
		pii vp = adj2[cur][i];
		if (vp.first == og) {
			ans[vp.second] = 2 * (nums[cur] - ans[adj2[cur][1-i].second]/2);
		}
	}
	for (int i = 0; i < M; i++) {
		cout << ans[i] << '\n';
	}

	cout.flush();
}

Compilation message

pipes.cpp: In function 'int main()':
pipes.cpp:103:17: warning: 'cur' may be used uninitialized in this function [-Wmaybe-uninitialized]
  sum += nums[cur];
         ~~~~~~~~^

Subtask #1
30.0 / 30.0

#	결과	실행 시간	메모리	Grader output
1	Correct	6 ms	4984 KB	Output is correct
2	Correct	6 ms	5248 KB	Output is correct
3	Correct	7 ms	5248 KB	Output is correct
4	Correct	118 ms	11276 KB	Output is correct
5	Correct	6 ms	11276 KB	Output is correct
6	Correct	6 ms	11276 KB	Output is correct
7	Correct	8 ms	11276 KB	Output is correct
8	Correct	6 ms	11276 KB	Output is correct
9	Correct	9 ms	11276 KB	Output is correct
10	Correct	8 ms	11276 KB	Output is correct
11	Correct	9 ms	11276 KB	Output is correct
12	Correct	6 ms	11276 KB	Output is correct
13	Correct	78 ms	11276 KB	Output is correct
14	Correct	82 ms	11276 KB	Output is correct
15	Correct	83 ms	11428 KB	Output is correct
16	Correct	88 ms	11428 KB	Output is correct
17	Correct	89 ms	11568 KB	Output is correct
18	Correct	91 ms	11568 KB	Output is correct
19	Correct	104 ms	14912 KB	Output is correct
20	Correct	6 ms	14912 KB	Output is correct
21	Correct	8 ms	14912 KB	Output is correct
22	Correct	92 ms	14912 KB	Output is correct
23	Correct	64 ms	14912 KB	Output is correct
24	Correct	81 ms	14912 KB	Output is correct
25	Correct	65 ms	14912 KB	Output is correct

Subtask #2
70.0 / 70.0

#	결과	실행 시간	메모리	Grader output
1	Correct	6 ms	14912 KB	Output is correct
2	Correct	7 ms	14912 KB	Output is correct
3	Correct	80 ms	14912 KB	Output is correct
4	Correct	62 ms	14912 KB	Output is correct
5	Correct	62 ms	14912 KB	Output is correct
6	Correct	262 ms	20332 KB	Output is correct
7	Correct	8 ms	20332 KB	Output is correct
8	Correct	6 ms	20332 KB	Output is correct
9	Correct	6 ms	20332 KB	Output is correct
10	Correct	6 ms	20332 KB	Output is correct
11	Correct	6 ms	20332 KB	Output is correct
12	Correct	6 ms	20332 KB	Output is correct
13	Correct	6 ms	20332 KB	Output is correct
14	Correct	6 ms	20332 KB	Output is correct
15	Correct	7 ms	20332 KB	Output is correct
16	Correct	7 ms	20332 KB	Output is correct
17	Correct	6 ms	20332 KB	Output is correct
18	Correct	7 ms	20332 KB	Output is correct
19	Correct	6 ms	20332 KB	Output is correct
20	Correct	6 ms	20332 KB	Output is correct
21	Correct	7 ms	20332 KB	Output is correct
22	Correct	7 ms	20332 KB	Output is correct
23	Correct	77 ms	20332 KB	Output is correct
24	Correct	99 ms	20332 KB	Output is correct
25	Correct	71 ms	20332 KB	Output is correct
26	Correct	68 ms	20332 KB	Output is correct
27	Correct	60 ms	20332 KB	Output is correct
28	Correct	74 ms	20332 KB	Output is correct
29	Correct	221 ms	20332 KB	Output is correct
30	Correct	98 ms	20332 KB	Output is correct
31	Correct	123 ms	20332 KB	Output is correct
32	Correct	87 ms	20332 KB	Output is correct
33	Correct	80 ms	20332 KB	Output is correct
34	Correct	60 ms	20332 KB	Output is correct
35	Correct	63 ms	20332 KB	Output is correct
36	Correct	63 ms	20332 KB	Output is correct
37	Correct	241 ms	20412 KB	Output is correct
38	Correct	127 ms	20412 KB	Output is correct
39	Correct	83 ms	20412 KB	Output is correct
40	Correct	103 ms	20412 KB	Output is correct
41	Correct	94 ms	20412 KB	Output is correct
42	Correct	56 ms	20412 KB	Output is correct
43	Correct	65 ms	20412 KB	Output is correct
44	Correct	58 ms	20412 KB	Output is correct
45	Correct	181 ms	20412 KB	Output is correct
46	Correct	91 ms	20412 KB	Output is correct
47	Correct	92 ms	20412 KB	Output is correct
48	Correct	107 ms	20412 KB	Output is correct
49	Correct	80 ms	20412 KB	Output is correct
50	Correct	61 ms	20412 KB	Output is correct
51	Correct	59 ms	20412 KB	Output is correct
52	Correct	65 ms	20412 KB	Output is correct
53	Correct	201 ms	20412 KB	Output is correct
54	Correct	90 ms	20412 KB	Output is correct

답안 #84111

Compilation message

Subtask #1 30.0 / 30.0

Subtask #2 70.0 / 70.0

Subtask #1
30.0 / 30.0

Subtask #2
70.0 / 70.0