#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int maxn = 1e5 + 10;
vector<pair<int,int>> g[maxn];
int h[maxn], up[maxn];
ll x[maxn], w[maxn];
vector<int> cyc;
bool mark[maxn];
void dfs3(int v, int idx = -1){
for (auto [u,i] : g[v]){
if (i == idx or !mark[u] or h[u] != -1)
continue;
h[u] = h[v] + 1;
dfs3(u,i);
x[v] -= w[i]/2;
}
if (idx != -1){
w[idx] = 2ll * x[v];
x[v] = 0;
}
}
void dfs2(int v, int idx = -1){
for (auto [u,i] : g[v]){
if (i == idx or h[u] != -1)
continue;
h[u] = h[v] + 1;
dfs2(u,i);
x[v] -= w[i] / 2;
}
if (!mark[v] and idx != -1){
w[idx] = 2ll * x[v];
x[v] = 0;
}
}
void dfs(int v){
up[v] = maxn;
for (auto [u,i] : g[v]){
if (h[u] == -1){
h[u] = h[v] + 1;
dfs(u);
up[v] = min(up[v], up[u]);
}
else if (h[u] != h[v]-1){
if (h[u] % 2 != h[v] % 2){
cout << 0 << endl;
exit(0);
}
up[v] = min(up[v], h[u]);
}
}
if (up[v] <= h[v]){
mark[v] = 1;
cyc.push_back(v);
}
}
int main(){
ios_base::sync_with_stdio(false);
int n, m;
cin >> n >> m;
if (m > n){
cout << 0 << endl;
exit(0);
}
for (int i = 1; i <= n; i++)
cin >> x[i];
for (int i = 0; i < m; i++){
int v, u;
cin >> v >> u;
g[v].push_back({u,i});
g[u].push_back({v,i});
}
memset(h, -1, sizeof h);
h[1] = 0;
dfs(1);
memset(h, -1, sizeof h);
int root = 1;
reverse(cyc.begin(), cyc.end());
if (!cyc.empty())
root = cyc[0];
h[root] = 0;
dfs2(root);
if (!cyc.empty()){
int v = cyc[0], u = cyc.back();
int idx = -1;
for (auto [w,i] : g[v])
if (u == w)
idx = i;
ll sign = 1;
for (int i = 0; i < cyc.size(); i++){
w[idx] += sign*2*x[cyc[i]];
sign *= -1;
}
w[idx] /= 2;
x[v] -= w[idx]/2;
x[u] -= w[idx]/2;
memset(h, -1, sizeof h);
h[root] = 0;
dfs3(root);
}
for (int i = 0; i < m; i++)
cout << w[i] << '\n';
}
Compilation message
pipes.cpp: In function 'void dfs3(int, int)':
pipes.cpp:17:12: warning: decomposition declaration only available with -std=c++1z or -std=gnu++1z
for (auto [u,i] : g[v]){
^
pipes.cpp: In function 'void dfs2(int, int)':
pipes.cpp:31:12: warning: decomposition declaration only available with -std=c++1z or -std=gnu++1z
for (auto [u,i] : g[v]){
^
pipes.cpp: In function 'void dfs(int)':
pipes.cpp:46:12: warning: decomposition declaration only available with -std=c++1z or -std=gnu++1z
for (auto [u,i] : g[v]){
^
pipes.cpp:46:16: warning: unused variable 'i' [-Wunused-variable]
for (auto [u,i] : g[v]){
^
pipes.cpp: In function 'int main()':
pipes.cpp:95:13: warning: decomposition declaration only available with -std=c++1z or -std=gnu++1z
for (auto [w,i] : g[v])
^
pipes.cpp:99:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for (int i = 0; i < cyc.size(); i++){
~~^~~~~~~~~~~~
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
2 ms |
3072 KB |
Output is correct |
| 2 |
Correct |
2 ms |
3072 KB |
Output is correct |
| 3 |
Correct |
4 ms |
3200 KB |
Output is correct |
| 4 |
Correct |
91 ms |
10232 KB |
Output is correct |
| 5 |
Correct |
2 ms |
3072 KB |
Output is correct |
| 6 |
Correct |
2 ms |
3072 KB |
Output is correct |
| 7 |
Correct |
3 ms |
3072 KB |
Output is correct |
| 8 |
Correct |
2 ms |
3072 KB |
Output is correct |
| 9 |
Correct |
3 ms |
3200 KB |
Output is correct |
| 10 |
Correct |
3 ms |
3200 KB |
Output is correct |
| 11 |
Correct |
3 ms |
3200 KB |
Output is correct |
| 12 |
Correct |
3 ms |
3200 KB |
Output is correct |
| 13 |
Correct |
58 ms |
9080 KB |
Output is correct |
| 14 |
Correct |
94 ms |
9976 KB |
Output is correct |
| 15 |
Correct |
89 ms |
10420 KB |
Output is correct |
| 16 |
Correct |
74 ms |
9336 KB |
Output is correct |
| 17 |
Correct |
87 ms |
10232 KB |
Output is correct |
| 18 |
Correct |
87 ms |
10232 KB |
Output is correct |
| 19 |
Correct |
103 ms |
12024 KB |
Output is correct |
| 20 |
Correct |
2 ms |
3072 KB |
Output is correct |
| 21 |
Correct |
3 ms |
3200 KB |
Output is correct |
| 22 |
Correct |
97 ms |
10232 KB |
Output is correct |
| 23 |
Correct |
66 ms |
8952 KB |
Output is correct |
| 24 |
Correct |
88 ms |
10232 KB |
Output is correct |
| 25 |
Correct |
69 ms |
9212 KB |
Output is correct |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
2 ms |
3072 KB |
Output is correct |
| 2 |
Correct |
3 ms |
3200 KB |
Output is correct |
| 3 |
Correct |
60 ms |
10616 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 |
3072 KB |
Output is correct |
| 8 |
Correct |
2 ms |
3072 KB |
Output is correct |
| 9 |
Correct |
2 ms |
3072 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 |
2688 KB |
Output is correct |
| 13 |
Correct |
2 ms |
2688 KB |
Output is correct |
| 14 |
Correct |
2 ms |
3072 KB |
Output is correct |
| 15 |
Correct |
3 ms |
3200 KB |
Output is correct |
| 16 |
Correct |
3 ms |
3200 KB |
Output is correct |
| 17 |
Correct |
3 ms |
3200 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 |
2 ms |
3200 KB |
Output is correct |
| 23 |
Correct |
71 ms |
11764 KB |
Output is correct |
| 24 |
Correct |
113 ms |
13048 KB |
Output is correct |
| 25 |
Correct |
58 ms |
10744 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 |
94 ms |
14196 KB |
Output is correct |
| 31 |
Correct |
138 ms |
14576 KB |
Output is correct |
| 32 |
Correct |
104 ms |
11384 KB |
Output is correct |
| 33 |
Correct |
109 ms |
11256 KB |
Output is correct |
| 34 |
Correct |
4 ms |
2688 KB |
Output is correct |
| 35 |
Correct |
2 ms |
2756 KB |
Output is correct |
| 36 |
Correct |
2 ms |
2688 KB |
Output is correct |
| 37 |
Correct |
2 ms |
2688 KB |
Output is correct |
| 38 |
Correct |
95 ms |
13812 KB |
Output is correct |
| 39 |
Correct |
80 ms |
11000 KB |
Output is correct |
| 40 |
Correct |
104 ms |
12732 KB |
Output is correct |
| 41 |
Correct |
70 ms |
12536 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 |
118 ms |
14576 KB |
Output is correct |
| 47 |
Correct |
107 ms |
12792 KB |
Output is correct |
| 48 |
Correct |
131 ms |
14372 KB |
Output is correct |
| 49 |
Correct |
63 ms |
9340 KB |
Output is correct |
| 50 |
Correct |
2 ms |
2688 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 |
93 ms |
13424 KB |
Output is correct |
