#include <bits/stdc++.h>
#define lsb(x) (x & (-x))
#define ll long long
#define ull unsigned long long
// 217
// 44
using namespace std;
const int MAXM = (int) 5e5;
const int MAXN = (int) 1e5;
vector < pair <int, int> > g[MAXN + 1];
int even[MAXN + 1], father[MAXN + 1], n;
bool vis[MAXN + 1];
void dfs(int nod) {
vis[nod] = 1;
for(auto it : g[nod]) {
if(vis[it.first] == 0) {
even[it.first] = (even[nod] ^ 1);
father[it.first] = nod;
dfs(it.first);
}
}
}
inline void detect_cycle(bool &cycle) {
memset(even, -1, sizeof(even));
even[1] = 0;
dfs(1);
int cnt = 0;
for(int i = 1; i <= n; i++) {
for(auto it : g[i]) {
if(even[i] != even[it.first] && !(father[it.first] == i || father[i] == it.first)) {
cout << 0;
exit(0);
}
if(even[i] == even[it.first]) {
cnt++;
}
}
}
cnt /= 2;
if(cnt > 1) {
cout << 0;
exit(0);
}
if(cnt) {
cycle = 1;
}
}
ll c[MAXN + 1];
ll sol[MAXM + 1];
int deg[MAXN + 1];
inline void check() {
for(int i = 1; i <= n; i++) {
if(c[i] != 0) {
cout << 0;
exit(0);
}
}
}
inline void solve_tree(bool cycle) {
int i;
memset(vis, 0, sizeof(vis));
queue <int> Q;
for(i = 1; i <= n; i++) {
if(g[i].size() == 1) {
Q.push(i);
vis[i] = 1;
}
}
while(Q.size()) {
int nod = Q.front();
Q.pop();
for(auto it : g[nod]) {
if(vis[it.first] == 0) {
deg[it.first]++;
sol[it.second] = c[nod];
c[it.first] -= c[nod];
c[nod] = 0;
if(deg[it.first] + 1 == g[it.first].size()) {
vis[it.first] = 1;
Q.push(it.first);
}
}
}
}
if(cycle == 0) {
check();
}
}
void dfs1(int nod, vector < pair <int, int> > &nodes, int par, int root) {
vis[nod] = 1;
for(auto it : g[nod]) {
if(it.first == par) {
continue;
}
if(vis[it.first] == 0) {
nodes.push_back({nod, it.second});
dfs1(it.first, nodes, nod, root);
}
else if(it.first == root) {
nodes.push_back({nod, it.second});
}
}
}
inline void solve_cycle(bool cycle) {
if(cycle == 0) {
return ;
}
int i, nod;
for(i = 1; i <= n; i++) {
if(vis[i] == 0) {
nod = i;
break;
}
}
vector < pair <int, int> > nodes;
dfs1(nod, nodes, 0, nod);
int sz = nodes.size();
ll tot = 0;
for(auto it : nodes) {
tot += c[it.first];
}
tot /= 2;
ll sum = 0;
for(i = 0; i + 1 < sz; i += 2) {
sum += c[nodes[i].first];
}
sol[nodes[sz - 2].second] = tot - sum;
c[nodes[sz - 2].first] -= tot - sum;
for(i = sz - 3; i >= 0; i--) {
sol[nodes[i].second] = c[nodes[i + 1].first];
c[nodes[i].first] -= sol[nodes[i].second];
}
sum = 0;
for(auto it : nodes) {
sum += sol[it.second];
}
sol[nodes.back().second] = tot - sum;
}
int main() {
//ifstream cin("A.in");
//ofstream cout("A.out");
int i, m;
ios::sync_with_stdio(false);
cin.tie(0), cout.tie(0);
cin >> n >> m;
for(i = 1; i <= n; i++) {
cin >> c[i];
c[i] *= 2LL;
}
for(i = 1; i <= m; i++) {
int x, y;
cin >> x >> y;
g[x].push_back({y, i});
g[y].push_back({x, i});
}
bool cycle = 0;
detect_cycle(cycle);
solve_tree(cycle);
solve_cycle(cycle);
for(i = 1; i <= m; i++) {
cout << sol[i] << "\n";
}
//cin.close();
//cout.close();
return 0;
}
Compilation message
pipes.cpp: In function 'void solve_tree(bool)':
pipes.cpp:87:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
if(deg[it.first] + 1 == g[it.first].size()) {
~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~
pipes.cpp: In function 'void solve_cycle(bool)':
pipes.cpp:127:9: warning: 'nod' may be used uninitialized in this function [-Wmaybe-uninitialized]
dfs1(nod, nodes, 0, nod);
~~~~^~~~~~~~~~~~~~~~~~~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
4 ms |
3192 KB |
Output isn't correct |
| 2 |
Incorrect |
4 ms |
3324 KB |
Output isn't correct |
| 3 |
Incorrect |
5 ms |
3396 KB |
Output isn't correct |
| 4 |
Incorrect |
80 ms |
9584 KB |
Output isn't correct |
| 5 |
Incorrect |
4 ms |
9584 KB |
Output isn't correct |
| 6 |
Incorrect |
5 ms |
9584 KB |
Output isn't correct |
| 7 |
Incorrect |
4 ms |
9584 KB |
Output isn't correct |
| 8 |
Incorrect |
4 ms |
9584 KB |
Output isn't correct |
| 9 |
Incorrect |
5 ms |
9584 KB |
Output isn't correct |
| 10 |
Incorrect |
5 ms |
9584 KB |
Output isn't correct |
| 11 |
Incorrect |
5 ms |
9584 KB |
Output isn't correct |
| 12 |
Incorrect |
5 ms |
9584 KB |
Output isn't correct |
| 13 |
Incorrect |
65 ms |
9584 KB |
Output isn't correct |
| 14 |
Incorrect |
81 ms |
9584 KB |
Output isn't correct |
| 15 |
Incorrect |
103 ms |
9856 KB |
Output isn't correct |
| 16 |
Incorrect |
71 ms |
9856 KB |
Output isn't correct |
| 17 |
Incorrect |
95 ms |
9856 KB |
Output isn't correct |
| 18 |
Incorrect |
85 ms |
9856 KB |
Output isn't correct |
| 19 |
Incorrect |
97 ms |
11204 KB |
Output isn't correct |
| 20 |
Incorrect |
4 ms |
11204 KB |
Output isn't correct |
| 21 |
Incorrect |
5 ms |
11204 KB |
Output isn't correct |
| 22 |
Incorrect |
81 ms |
11204 KB |
Output isn't correct |
| 23 |
Incorrect |
64 ms |
11204 KB |
Output isn't correct |
| 24 |
Incorrect |
81 ms |
11204 KB |
Output isn't correct |
| 25 |
Incorrect |
66 ms |
11204 KB |
Output isn't correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
4 ms |
11204 KB |
Output is correct |
| 2 |
Correct |
5 ms |
11204 KB |
Output is correct |
| 3 |
Correct |
75 ms |
11204 KB |
Output is correct |
| 4 |
Correct |
81 ms |
11476 KB |
Output is correct |
| 5 |
Correct |
72 ms |
11476 KB |
Output is correct |
| 6 |
Correct |
281 ms |
22396 KB |
Output is correct |
| 7 |
Correct |
4 ms |
22396 KB |
Output is correct |
| 8 |
Correct |
5 ms |
22396 KB |
Output is correct |
| 9 |
Correct |
4 ms |
22396 KB |
Output is correct |
| 10 |
Correct |
4 ms |
22396 KB |
Output is correct |
| 11 |
Correct |
4 ms |
22396 KB |
Output is correct |
| 12 |
Correct |
4 ms |
22396 KB |
Output is correct |
| 13 |
Correct |
4 ms |
22396 KB |
Output is correct |
| 14 |
Correct |
4 ms |
22396 KB |
Output is correct |
| 15 |
Correct |
5 ms |
22396 KB |
Output is correct |
| 16 |
Correct |
5 ms |
22396 KB |
Output is correct |
| 17 |
Correct |
5 ms |
22396 KB |
Output is correct |
| 18 |
Correct |
5 ms |
22396 KB |
Output is correct |
| 19 |
Correct |
5 ms |
22396 KB |
Output is correct |
| 20 |
Correct |
5 ms |
22396 KB |
Output is correct |
| 21 |
Correct |
5 ms |
22396 KB |
Output is correct |
| 22 |
Correct |
5 ms |
22396 KB |
Output is correct |
| 23 |
Correct |
97 ms |
22396 KB |
Output is correct |
| 24 |
Correct |
102 ms |
22396 KB |
Output is correct |
| 25 |
Correct |
66 ms |
22396 KB |
Output is correct |
| 26 |
Correct |
76 ms |
22396 KB |
Output is correct |
| 27 |
Correct |
77 ms |
22396 KB |
Output is correct |
| 28 |
Correct |
70 ms |
22396 KB |
Output is correct |
| 29 |
Correct |
214 ms |
22396 KB |
Output is correct |
| 30 |
Correct |
103 ms |
22396 KB |
Output is correct |
| 31 |
Correct |
107 ms |
22396 KB |
Output is correct |
| 32 |
Correct |
96 ms |
22396 KB |
Output is correct |
| 33 |
Correct |
71 ms |
22396 KB |
Output is correct |
| 34 |
Correct |
76 ms |
22396 KB |
Output is correct |
| 35 |
Correct |
78 ms |
22396 KB |
Output is correct |
| 36 |
Correct |
68 ms |
22396 KB |
Output is correct |
| 37 |
Correct |
257 ms |
22444 KB |
Output is correct |
| 38 |
Correct |
106 ms |
22444 KB |
Output is correct |
| 39 |
Correct |
100 ms |
22444 KB |
Output is correct |
| 40 |
Correct |
105 ms |
22444 KB |
Output is correct |
| 41 |
Correct |
80 ms |
22444 KB |
Output is correct |
| 42 |
Correct |
85 ms |
22444 KB |
Output is correct |
| 43 |
Correct |
79 ms |
22444 KB |
Output is correct |
| 44 |
Correct |
75 ms |
22444 KB |
Output is correct |
| 45 |
Correct |
197 ms |
22444 KB |
Output is correct |
| 46 |
Correct |
106 ms |
22444 KB |
Output is correct |
| 47 |
Correct |
99 ms |
22444 KB |
Output is correct |
| 48 |
Correct |
104 ms |
22444 KB |
Output is correct |
| 49 |
Correct |
60 ms |
22444 KB |
Output is correct |
| 50 |
Correct |
73 ms |
22444 KB |
Output is correct |
| 51 |
Correct |
69 ms |
22444 KB |
Output is correct |
| 52 |
Correct |
72 ms |
22444 KB |
Output is correct |
| 53 |
Correct |
221 ms |
22444 KB |
Output is correct |
| 54 |
Correct |
104 ms |
22444 KB |
Output is correct |
