#include <bits/stdc++.h>
using namespace std;
int main() {
ios::sync_with_stdio(false);
cin.tie(0);
int n, m;
cin >> n >> m;
vector<long long> a(n);
for (int i = 0; i < n; i++) {
cin >> a[i];
}
vector<vector<array<int, 2>>> g(n);
for (int i = 0; i < m; i++) {
int x, y;
cin >> x >> y;
--x; --y;
g[x].push_back({y, i});
g[y].push_back({x, i});
}
if (m > n) {
cout << 0 << '\n';
return 0;
}
if (n == 1) {
cout << 2 * a[0] << '\n';
return 0;
}
if (m < n) {
vector<long long> res(m);
function<void(int, int)> Dfs = [&](int v, int pv) {
for (auto& e : g[v]) {
int u = e[0];
if (u == pv) {
continue;
}
Dfs(u, v);
if (a[u] != 0) {
res[e[1]] = 2 * a[u];
a[v] -= a[u];
}
}
};
Dfs(0, 0);
if (a[0] != 0) {
cout << 0 << '\n';
return 0;
}
for (int i = 0; i < m; i++) {
cout << res[i] << '\n';
}
return 0;
}
vector<int> deg(n);
for (int i = 0; i < n; i++) {
deg[i] = (int) g[i].size();
}
vector<int> que;
for (int i = 0; i < n; i++) {
if (deg[i] == 1) {
que.push_back(i);
}
}
auto orig = a;
vector<long long> res(m);
for (int b = 0; b < (int) que.size(); b++) {
int i = que[b];
for (auto& e : g[i]) {
int j = e[0];
deg[j] -= 1;
if (deg[j] == 1) {
que.push_back(j);
res[e[1]] = 2 * a[i];
a[j] -= a[i];
a[i] = 0;
}
}
}
vector<int> cyc;
for (int i = 0; i < n; i++) {
if (deg[i] > 1) {
cyc.push_back(i);
}
}
for (int i : cyc) {
for (auto& e : g[i]) {
int j = e[0];
if (deg[j] < 2) {
res[e[1]] = 2 * a[j];
a[i] -= a[j];
a[j] = 0;
}
}
}
if ((int) cyc.size() % 2 == 0) {
cout << 0 << '\n';
return 0;
}
vector<bool> was(n);
vector<long long> vals;
vector<int> ids;
function<void(int)> Dfs = [&](int v) {
was[v] = true;
vals.push_back(a[v]);
int back = -1;
bool found = false;
for (auto& e : g[v]) {
int u = e[0];
int i = e[1];
if (u == cyc[0]) {
back = i;
}
if (was[u] || deg[u] <= 1) {
continue;
}
found = true;
ids.push_back(i);
Dfs(u);
}
if (!found) {
ids.push_back(back);
}
};
Dfs(cyc[0]);
long long total = 0;
for (int i = 0; i < (int) vals.size(); i++) {
total = vals[i] - total;
}
if (total % 2 == 1) {
cout << 0 << '\n';
return 0;
}
total /= 2;
res[ids.back()] = 2 * total;
for (int i = 0; i < n; i++) {
for (auto& p : g[i]) {
if (p[1] == ids.back()) {
a[i] -= total;
}
}
}
was = vector<bool>(n, false);
Dfs = [&](int v) {
was[v] = true;
for (auto& p : g[v]) {
int u = p[0];
int i = p[1];
if (deg[u] <= 1 || was[u] || i == ids.back()) {
continue;
}
Dfs(u);
res[i] = 2 * a[u];
a[v] -= a[u];
a[u] = 0;
}
};
Dfs(cyc.back());
a = orig;
for (int i = 0; i < n; i++) {
long long sum = 0;
for (auto& p : g[i]) {
sum += res[p[1]] / 2;
}
if (sum != a[i]) {
cout << 0 << '\n';
return 0;
}
}
for (int i = 0; i < m; i++) {
cout << res[i] << '\n';
}
return 0;
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
344 KB |
Output is correct |
2 |
Correct |
0 ms |
344 KB |
Output is correct |
3 |
Correct |
0 ms |
348 KB |
Output is correct |
4 |
Correct |
41 ms |
8416 KB |
Output is correct |
5 |
Correct |
0 ms |
348 KB |
Output is correct |
6 |
Correct |
0 ms |
348 KB |
Output is correct |
7 |
Correct |
0 ms |
348 KB |
Output is correct |
8 |
Correct |
0 ms |
348 KB |
Output is correct |
9 |
Correct |
1 ms |
424 KB |
Output is correct |
10 |
Correct |
1 ms |
348 KB |
Output is correct |
11 |
Correct |
1 ms |
348 KB |
Output is correct |
12 |
Correct |
1 ms |
348 KB |
Output is correct |
13 |
Correct |
29 ms |
6652 KB |
Output is correct |
14 |
Correct |
39 ms |
7936 KB |
Output is correct |
15 |
Correct |
33 ms |
8528 KB |
Output is correct |
16 |
Correct |
27 ms |
7256 KB |
Output is correct |
17 |
Correct |
33 ms |
8276 KB |
Output is correct |
18 |
Correct |
36 ms |
8532 KB |
Output is correct |
19 |
Correct |
37 ms |
12380 KB |
Output is correct |
20 |
Correct |
1 ms |
348 KB |
Output is correct |
21 |
Correct |
1 ms |
348 KB |
Output is correct |
22 |
Correct |
33 ms |
8536 KB |
Output is correct |
23 |
Correct |
27 ms |
6744 KB |
Output is correct |
24 |
Correct |
33 ms |
8532 KB |
Output is correct |
25 |
Correct |
27 ms |
7000 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
0 ms |
348 KB |
Output isn't correct |
2 |
Incorrect |
0 ms |
604 KB |
Output isn't correct |
3 |
Correct |
27 ms |
8980 KB |
Output is correct |
4 |
Correct |
22 ms |
6844 KB |
Output is correct |
5 |
Correct |
23 ms |
7000 KB |
Output is correct |
6 |
Correct |
99 ms |
17204 KB |
Output is correct |
7 |
Incorrect |
0 ms |
348 KB |
Output isn't correct |
8 |
Correct |
0 ms |
348 KB |
Output is correct |
9 |
Correct |
0 ms |
348 KB |
Output is correct |
10 |
Correct |
0 ms |
348 KB |
Output is correct |
11 |
Correct |
0 ms |
348 KB |
Output is correct |
12 |
Correct |
0 ms |
348 KB |
Output is correct |
13 |
Correct |
0 ms |
348 KB |
Output is correct |
14 |
Incorrect |
0 ms |
344 KB |
Output isn't correct |
15 |
Incorrect |
0 ms |
604 KB |
Output isn't correct |
16 |
Correct |
0 ms |
348 KB |
Output is correct |
17 |
Correct |
0 ms |
348 KB |
Output is correct |
18 |
Correct |
0 ms |
348 KB |
Output is correct |
19 |
Correct |
1 ms |
344 KB |
Output is correct |
20 |
Correct |
1 ms |
348 KB |
Output is correct |
21 |
Correct |
1 ms |
348 KB |
Output is correct |
22 |
Incorrect |
1 ms |
348 KB |
Output isn't correct |
23 |
Incorrect |
28 ms |
13320 KB |
Output isn't correct |
24 |
Incorrect |
38 ms |
15112 KB |
Output isn't correct |
25 |
Correct |
26 ms |
9040 KB |
Output is correct |
26 |
Correct |
25 ms |
6748 KB |
Output is correct |
27 |
Correct |
29 ms |
6492 KB |
Output is correct |
28 |
Correct |
29 ms |
7080 KB |
Output is correct |
29 |
Correct |
88 ms |
14672 KB |
Output is correct |
30 |
Correct |
43 ms |
14156 KB |
Output is correct |
31 |
Incorrect |
40 ms |
18892 KB |
Output isn't correct |
32 |
Incorrect |
34 ms |
11468 KB |
Output isn't correct |
33 |
Correct |
31 ms |
9364 KB |
Output is correct |
34 |
Correct |
24 ms |
6748 KB |
Output is correct |
35 |
Correct |
31 ms |
6760 KB |
Output is correct |
36 |
Correct |
23 ms |
7036 KB |
Output is correct |
37 |
Correct |
95 ms |
17232 KB |
Output is correct |
38 |
Incorrect |
38 ms |
14156 KB |
Output isn't correct |
39 |
Incorrect |
29 ms |
10700 KB |
Output isn't correct |
40 |
Incorrect |
34 ms |
14676 KB |
Output isn't correct |
41 |
Correct |
25 ms |
9420 KB |
Output is correct |
42 |
Correct |
24 ms |
6492 KB |
Output is correct |
43 |
Correct |
27 ms |
6748 KB |
Output is correct |
44 |
Correct |
22 ms |
6952 KB |
Output is correct |
45 |
Correct |
69 ms |
14412 KB |
Output is correct |
46 |
Incorrect |
34 ms |
13652 KB |
Output isn't correct |
47 |
Incorrect |
45 ms |
14676 KB |
Output isn't correct |
48 |
Incorrect |
49 ms |
18372 KB |
Output isn't correct |
49 |
Correct |
27 ms |
9168 KB |
Output is correct |
50 |
Correct |
23 ms |
6748 KB |
Output is correct |
51 |
Correct |
24 ms |
7000 KB |
Output is correct |
52 |
Correct |
22 ms |
6736 KB |
Output is correct |
53 |
Correct |
79 ms |
14676 KB |
Output is correct |
54 |
Correct |
40 ms |
13656 KB |
Output is correct |