Submission #444005

# Submission time Handle Problem Language Result Execution time Memory
444005 2021-07-12T20:54:24 Z aryan12 Pipes (BOI13_pipes) C++17
100 / 100
244 ms 29484 KB
#include <bits/stdc++.h>
using namespace std;
#define int long long

mt19937_64 RNG(chrono::steady_clock::now().time_since_epoch().count());

const int N = 1e5 + 5;
int change[N], result[N];
vector<pair<int, int> > g[N];
int edgeChange[N], temp[N];
bool vis[N];
int n, m, bruh;
vector<int> cycle, cycle_edges;

void dfs(int node, int par, int edgeNum) {
	for(int i = 0; i < g[node].size(); i++) {
		if(g[node][i].first != par) {
			dfs(g[node][i].first, node, g[node][i].second);
		}
	}
	int netWithParent = change[node] - result[node];
	if(par != -1) {
		result[node] += netWithParent;
		edgeChange[edgeNum] = netWithParent;
		result[par] += netWithParent;
	}
}

void Tree() {
	dfs(1, -1, -1);
	if(result[1] != change[1]) {
		cout << "0\n";
		return;
	}
	for(int i = 1; i <= m; i++) {
		cout << edgeChange[i] * 2 << "\n";
	}
}

void dfs1(int node, int par) {
	vis[node] = true;
	cycle.push_back(node);
	for(int i = 0; i < g[node].size(); i++) {
		if(g[node][i].first == par) {
			continue;
		}
		if(!vis[g[node][i].first]) {
			cycle_edges.push_back(g[node][i].second);
			dfs1(g[node][i].first, node);
		}
		if(g[node][i].first == bruh) {
			cycle_edges.push_back(g[node][i].second);
		}
	}
}

void Solve() {
	cin >> n >> m;
	for(int i = 1; i <= n; i++) {
		cin >> change[i];
	}
	for(int i = 1; i <= m; i++) {
		int u, v;
		cin >> u >> v;
		g[u].push_back(make_pair(v, i));
		g[v].push_back(make_pair(u, i));
	}
	if(m == n - 1) {
		Tree();
		return;
	}
	if(m > n) {
		cout << "0\n";
		return;
	}
	int cnt = 0;
	queue<int> q;
	for(int i = 1; i <= n; i++) {
		vis[i] = false;
		temp[i] = g[i].size();
		if(temp[i] == 1) {
			q.push(i);
		}
	}
	while(!q.empty()) {
		int node = q.front();
		vis[node] = true;
		q.pop();
		cnt++;
		for(int i = 0; i < g[node].size(); i++) {
			if(!vis[g[node][i].first]) {
				temp[g[node][i].first]--;
				if(temp[g[node][i].first] == 1) {
					q.push(g[node][i].first);
				}
				int netChange = change[node] - result[node];
				edgeChange[g[node][i].second] = netChange;
				result[node] += netChange;
				result[g[node][i].first] += netChange;
			}
		}
	}
	if((n - cnt) % 2 == 0) {
		cout << "0\n";
		return;
	}
	for(int i = 1; i <= n; i++) {
		if(!vis[i]) {
			bruh = i;
			dfs1(i, -1);
		}
	}
	/*for(int i = 1; i <= n; i++) {
		cout << "change[i] = " << change[i] << ", result[i] = " << result[i] << "\n";
	}*/
	int sum = 0;
	for(int i = 0; i < cycle.size(); i++) {
		if(i % 2 == 1) {
			sum -= (change[cycle[i]] - result[cycle[i]]);
		}
		else {
			sum += (change[cycle[i]] - result[cycle[i]]);
		}
	}
	if(sum % 2 == 1) {
		cout << "0\n";
		return;
	}
	//cout << "sum = " << sum << "\n";
	edgeChange[cycle_edges[cycle_edges.size() - 1]] = sum / 2;
	edgeChange[cycle_edges[0]] = change[cycle[0]] - result[cycle[0]] - edgeChange[cycle_edges[cycle_edges.size() - 1]];
	/*for(int i = 0; i < cycle_edges.size(); i++) {
		cout << cycle_edges[i] << " ";
	}
	cout << "\n";
	for(int i = 0; i < cycle.size(); i++) {
		cout << cycle[i] << " ";
	}
	cout << "\n";*/
	for(int i = 1; i < cycle_edges.size() - 1; i++) {
		edgeChange[cycle_edges[i]] = change[cycle[i]] - result[cycle[i]] - edgeChange[cycle_edges[i - 1]];
	}
	for(int i = 1; i <= m; i++) {
		cout << edgeChange[i] * 2 << "\n";
	}
}

int32_t main() {
	auto begin = std::chrono::high_resolution_clock::now();
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	int t = 1;
	//cin >> t;
	while(t--) {
		Solve();
	}
	auto end = std::chrono::high_resolution_clock::now();
    auto elapsed = std::chrono::duration_cast<std::chrono::nanoseconds>(end - begin);
    cerr << "Time measured: " << elapsed.count() * 1e-9 << " seconds.\n"; 
	return 0;
}

Compilation message

pipes.cpp: In function 'void dfs(long long int, long long int, long long int)':
pipes.cpp:16:19: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   16 |  for(int i = 0; i < g[node].size(); i++) {
      |                 ~~^~~~~~~~~~~~~~~~
pipes.cpp: In function 'void dfs1(long long int, long long int)':
pipes.cpp:43:19: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   43 |  for(int i = 0; i < g[node].size(); i++) {
      |                 ~~^~~~~~~~~~~~~~~~
pipes.cpp: In function 'void Solve()':
pipes.cpp:90:20: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   90 |   for(int i = 0; i < g[node].size(); i++) {
      |                  ~~^~~~~~~~~~~~~~~~
pipes.cpp:117:19: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  117 |  for(int i = 0; i < cycle.size(); i++) {
      |                 ~~^~~~~~~~~~~~~~
pipes.cpp:140:19: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  140 |  for(int i = 1; i < cycle_edges.size() - 1; i++) {
      |                 ~~^~~~~~~~~~~~~~~~~~~~~~~~
# 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 2764 KB Output is correct
4 Correct 71 ms 10480 KB Output is correct
5 Correct 2 ms 2636 KB Output is correct
6 Correct 2 ms 2636 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 2764 KB Output is correct
10 Correct 3 ms 2764 KB Output is correct
11 Correct 2 ms 2764 KB Output is correct
12 Correct 2 ms 2764 KB Output is correct
13 Correct 51 ms 8852 KB Output is correct
14 Correct 67 ms 10084 KB Output is correct
15 Correct 82 ms 10528 KB Output is correct
16 Correct 59 ms 9284 KB Output is correct
17 Correct 79 ms 10452 KB Output is correct
18 Correct 70 ms 10532 KB Output is correct
19 Correct 73 ms 13672 KB Output is correct
20 Correct 2 ms 2636 KB Output is correct
21 Correct 3 ms 2764 KB Output is correct
22 Correct 87 ms 10568 KB Output is correct
23 Correct 54 ms 8904 KB Output is correct
24 Correct 68 ms 10556 KB Output is correct
25 Correct 58 ms 9156 KB Output is correct
# 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 64 ms 10780 KB Output is correct
4 Correct 51 ms 8588 KB Output is correct
5 Correct 70 ms 8388 KB Output is correct
6 Correct 214 ms 29368 KB Output is correct
7 Correct 2 ms 2636 KB Output is correct
8 Correct 2 ms 2596 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 2636 KB Output is correct
13 Correct 2 ms 2636 KB Output is correct
14 Correct 3 ms 2724 KB Output is correct
15 Correct 3 ms 2892 KB Output is correct
16 Correct 2 ms 2764 KB Output is correct
17 Correct 2 ms 2764 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 2 ms 2764 KB Output is correct
22 Correct 2 ms 2764 KB Output is correct
23 Correct 67 ms 14896 KB Output is correct
24 Correct 78 ms 16712 KB Output is correct
25 Correct 52 ms 10820 KB Output is correct
26 Correct 56 ms 8656 KB Output is correct
27 Correct 51 ms 8552 KB Output is correct
28 Correct 52 ms 8876 KB Output is correct
29 Correct 172 ms 24068 KB Output is correct
30 Correct 81 ms 15608 KB Output is correct
31 Correct 118 ms 19820 KB Output is correct
32 Correct 73 ms 13256 KB Output is correct
33 Correct 56 ms 11260 KB Output is correct
34 Correct 53 ms 8576 KB Output is correct
35 Correct 52 ms 8660 KB Output is correct
36 Correct 47 ms 8680 KB Output is correct
37 Correct 244 ms 29484 KB Output is correct
38 Correct 82 ms 16080 KB Output is correct
39 Correct 73 ms 12660 KB Output is correct
40 Correct 75 ms 16256 KB Output is correct
41 Correct 52 ms 11044 KB Output is correct
42 Correct 47 ms 8536 KB Output is correct
43 Correct 51 ms 8516 KB Output is correct
44 Correct 48 ms 8404 KB Output is correct
45 Correct 162 ms 26848 KB Output is correct
46 Correct 96 ms 15420 KB Output is correct
47 Correct 77 ms 16416 KB Output is correct
48 Correct 83 ms 19600 KB Output is correct
49 Correct 56 ms 10820 KB Output is correct
50 Correct 47 ms 8644 KB Output is correct
51 Correct 68 ms 8712 KB Output is correct
52 Correct 46 ms 8516 KB Output is correct
53 Correct 166 ms 25924 KB Output is correct
54 Correct 78 ms 15056 KB Output is correct