oj.uz

Submission #158021

# Submission time Handle Problem Language Result Execution time Memory
158021 2019-10-14T13:00:21 Z DrSwad Pipes (BOI13_pipes) C++14
100 / 100
 645 ms 63176 KB 
#include <bits/stdc++.h>

using namespace std;

#ifdef LOCAL
#include "debug.h"
#endif

typedef long long ll;
typedef pair<int, int> pii;

#define x first
#define y second

const int N = 1e5 + 5;

int n, m;
vector<int> c;
vector<set<int>> adj;
vector<pii> e;
vector<ll> ans;

int adjacentNode(int node, int i) {
	assert(i == 0 || i == 1);
	int adj_edge = (i == 0 ? *adj[node].begin() : *adj[node].rbegin());
	int adj_node = e[adj_edge].x ^ e[adj_edge].y ^ node;
	return adj_node;
}

void dfs(int at, int p, int root, vector<pii> &order) {
	int nxt;

	nxt = adjacentNode(at, 0);
	if (nxt != p) order.push_back({at, *adj[at].begin()});
	else {
		nxt = adjacentNode(at, 1);
		if (nxt != p) order.push_back({at, *adj[at].rbegin()});
	}

	if (nxt != root) dfs(nxt, at, root, order);
}

int main() {
	#ifdef LOCAL
	freopen("in", "r", stdin);
	freopen("out", "w", stdout);
	#endif

	scanf("%d %d", &n, &m);

	c.resize(n);
	for (int i = 0; i < n; i++) scanf("%d", &c[i]);

	adj.resize(n);
	e.resize(m);
	for (int i = 0; i < m; i++) {
		int u, v;
		scanf("%d %d", &u, &v);
		u--, v--;
		adj[u].insert(i);
		adj[v].insert(i);
		e[i] = {u, v};
	}

	ans.resize(m);
	queue<int> q;
	for (int i = 0; i < n; i++) q.push(i);

	while (!q.empty()) {
		 int curr_node = q.front(); q.pop();
		 if (adj[curr_node].size() == 1) {
		 	int adj_edge = *adj[curr_node].begin();
		 	int adj_node = adjacentNode(curr_node, 0);

		 	ans[adj_edge] = 2LL * c[curr_node];
		 	c[curr_node] -= ans[adj_edge] / 2;
		 	c[adj_node] -= ans[adj_edge] / 2;

		 	adj[curr_node].erase(adj_edge);
		 	adj[adj_node].erase(adj_edge);

		 	if (adj[adj_node].size() == 1) q.push(adj_node);
		 }
	}

	int cnt_node = 0;
	for (int i = 0; i < n; i++) {
		if (adj[i].size() > 2) {
			printf("0\n");
			return 0;
		}
		cnt_node += adj[i].size() == 2;
	}

	if (cnt_node > 0 && cnt_node % 2 == 0) {
		printf("0\n");
		return 0;
	}

	int first_node;
	for (first_node = 0; first_node < n; first_node++) {
		if (adj[first_node].size() == 2) break;
	}

	if (first_node < n) {
		vector<pii> order;
		dfs(first_node, -1, first_node, order);

		ll sum = 2LL * c[first_node];
		ll diff = 0;
		for (int i = 1; i < order.size(); i++) {
			diff = 2LL * c[order[i].x] - diff;
		}

		ans[order[0].y] = (sum - diff) / 2LL;

		for (int i = 1; i < order.size(); i++) {
			ans[order[i].y] = 2LL * c[order[i].x] - ans[order[i - 1].y];
		}
	}

	for (int i = 0; i < m; i++) printf("%lld\n", ans[i]);

	return 0;
}

Compilation message

pipes.cpp: In function 'int main()':
pipes.cpp:111:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for (int i = 1; i < order.size(); i++) {
                   ~~^~~~~~~~~~~~~~
pipes.cpp:117:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for (int i = 1; i < order.size(); i++) {
                   ~~^~~~~~~~~~~~~~
pipes.cpp:49:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d %d", &n, &m);
  ~~~~~^~~~~~~~~~~~~~~~~
pipes.cpp:52:35: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  for (int i = 0; i < n; i++) scanf("%d", &c[i]);
                              ~~~~~^~~~~~~~~~~~~
pipes.cpp:58:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d %d", &u, &v);
   ~~~~~^~~~~~~~~~~~~~~~~

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 2 ms 376 KB Output is correct
3 Correct 3 ms 504 KB Output is correct
4 Correct 161 ms 18504 KB Output is correct
5 Correct 2 ms 256 KB Output is correct
6 Correct 2 ms 256 KB Output is correct
7 Correct 2 ms 376 KB Output is correct
8 Correct 2 ms 376 KB Output is correct
9 Correct 3 ms 504 KB Output is correct
10 Correct 3 ms 504 KB Output is correct
11 Correct 3 ms 504 KB Output is correct
12 Correct 3 ms 504 KB Output is correct
13 Correct 119 ms 14712 KB Output is correct
14 Correct 149 ms 17756 KB Output is correct
15 Correct 168 ms 18720 KB Output is correct
16 Correct 163 ms 15516 KB Output is correct
17 Correct 153 ms 18632 KB Output is correct
18 Correct 150 ms 18760 KB Output is correct
19 Correct 142 ms 18760 KB Output is correct
20 Correct 2 ms 376 KB Output is correct
21 Correct 3 ms 504 KB Output is correct
22 Correct 165 ms 18760 KB Output is correct
23 Correct 123 ms 14968 KB Output is correct
24 Correct 164 ms 18888 KB Output is correct
25 Correct 179 ms 15640 KB Output is correct

Subtask #2
70.0 / 70.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 3 ms 504 KB Output is correct
3 Correct 151 ms 17360 KB Output is correct
4 Correct 114 ms 18296 KB Output is correct
5 Correct 126 ms 17912 KB Output is correct
6 Correct 645 ms 63176 KB Output is correct
7 Correct 2 ms 376 KB Output is correct
8 Correct 2 ms 360 KB Output is correct
9 Correct 2 ms 376 KB Output is correct
10 Correct 2 ms 376 KB Output is correct
11 Correct 2 ms 376 KB Output is correct
12 Correct 2 ms 376 KB Output is correct
13 Correct 2 ms 376 KB Output is correct
14 Correct 2 ms 376 KB Output is correct
15 Correct 3 ms 632 KB Output is correct
16 Correct 3 ms 504 KB Output is correct
17 Correct 3 ms 504 KB Output is correct
18 Correct 3 ms 504 KB Output is correct
19 Correct 3 ms 504 KB Output is correct
20 Correct 3 ms 508 KB Output is correct
21 Correct 4 ms 760 KB Output is correct
22 Correct 3 ms 496 KB Output is correct
23 Correct 122 ms 18664 KB Output is correct
24 Correct 144 ms 22052 KB Output is correct
25 Correct 113 ms 17344 KB Output is correct
26 Correct 112 ms 18476 KB Output is correct
27 Correct 98 ms 18184 KB Output is correct
28 Correct 127 ms 18552 KB Output is correct
29 Correct 494 ms 52224 KB Output is correct
30 Correct 144 ms 21308 KB Output is correct
31 Correct 138 ms 24384 KB Output is correct
32 Correct 160 ms 19716 KB Output is correct
33 Correct 122 ms 18300 KB Output is correct
34 Correct 98 ms 18296 KB Output is correct
35 Correct 99 ms 18552 KB Output is correct
36 Correct 124 ms 18652 KB Output is correct
37 Correct 628 ms 63100 KB Output is correct
38 Correct 145 ms 21596 KB Output is correct
39 Correct 152 ms 19240 KB Output is correct
40 Correct 149 ms 21836 KB Output is correct
41 Correct 101 ms 18400 KB Output is correct
42 Correct 98 ms 18424 KB Output is correct
43 Correct 98 ms 18312 KB Output is correct
44 Correct 136 ms 17944 KB Output is correct
45 Correct 614 ms 54116 KB Output is correct
46 Correct 136 ms 21252 KB Output is correct
47 Correct 152 ms 21948 KB Output is correct
48 Correct 138 ms 24428 KB Output is correct
49 Correct 134 ms 17304 KB Output is correct
50 Correct 137 ms 18296 KB Output is correct
51 Correct 130 ms 18384 KB Output is correct
52 Correct 99 ms 18148 KB Output is correct
53 Correct 564 ms 55900 KB Output is correct
54 Correct 153 ms 20896 KB Output is correct