QOJ.ac
QOJ
| ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
|---|---|---|---|---|---|---|---|---|---|
| #75420 | #5307. Subgraph Isomorphism | team1377# | WA | 49ms | 6312kb | C++14 | 4.1kb | 2023-02-05 10:02:43 | 2023-10-15 17:24:14 |
Judging History
answer
#include <bits/stdc++.h>
using namespace std;
const int N = 1e5 + 5;
vector<int> G[N];
int dep[N];
void dfs(int x)
{
for (int i = 0; i < G[x].size(); ++i) {
if (!dep[G[x][i]]) {
dep[G[x][i]] = dep[x] + 1;
dfs(G[x][i]);
}
}
return;
}
int dis(int x, int y)
{
memset(dep, 0, sizeof(dep));
dep[x] = 1;
dfs(x);
return dep[y] - 1;
}
signed main()
{
int T;
scanf("%d", &T);
while (T--) {
int n, m;
scanf("%d%d", &n, &m);
for (int i = 1; i <= n; ++i) {
G[i].clear();
}
for (int i = 1; i <= m; ++i) {
int x, y;
scanf("%d%d", &x, &y);
G[x].push_back(y);
G[y].push_back(x);
}
if (m == n - 1) {
puts("YES");
} else if (m != n) {
puts("NO");
} else {
int flag = 1;
for (int i = 1; i <= n; ++i) {
if (G[i].size() != 2) {
flag = 0;
break;
}
}
if (flag) {
puts("YES");
} else {
if ((n & 1) || n < 6) {
puts("NO");
continue;
}
int wh1 = 0, wh2 = 0;
for (int i = 1; i <= n; ++i) {
if (G[i].size() == 1) {
if (!wh1) {
wh1 = i;
} else {
if (!wh2) {
wh2 = i;
} else {
wh2 = -1;
break;
}
}
}
}
if (!~wh2 || !wh2) {
puts("NO");
} else {
int wh3 = 0, wh4 = 0;
for (int i = 1; i <= n; ++i) {
if (G[i].size() == 3) {
if (!wh3) {
wh3 = i;
} else {
if (!wh4) {
wh4 = i;
} else {
wh4 = -1;
break;
}
}
}
}
if (!~wh4 || !wh4) {
puts("NO");
} else {
int wh5 = 0, wh6 = 0;
for (int i = 1; i <= n; ++i) {
if (G[i].size() == 2 && ((G[i][0] == wh3 && G[i][1] == wh4) || (G[i][0] == wh4 && G[i][1] == wh3))) {
if (!wh5) {
wh5 = i;
} else {
if (!wh6) {
wh6 = i;
} else {
wh6 = -1;
break;
}
}
}
}
if (!~wh6 || !wh6) {
puts("NO");
} else {
flag = 1;
for (int i = 1; i <= n; ++i) {
flag &= (G[i].size() <= 3);
}
if (flag && dis(wh1, wh2) == n - 2 && ((dis(wh1, wh3) == n / 2 - 2 && dis(wh2, wh4) == n / 2 - 2) || (dis(wh1, wh4) == n / 2 - 2 && dis(wh2, wh3) == n / 2 - 2))) {
puts("YES");
} else {
puts("NO");
}
}
}
}
}
}
}
return 0;
}
Details
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Test #1:
score: 100
Accepted
time: 1ms
memory: 5840kb
input:
4 7 6 1 2 2 3 3 4 4 5 5 6 3 7 3 3 1 2 2 3 3 1 5 5 1 2 2 3 3 4 4 1 1 5 1 0
output:
YES YES NO YES
result:
ok 4 token(s): yes count is 3, no count is 1
Test #2:
score: -100
Wrong Answer
time: 49ms
memory: 6312kb
input:
33192 2 1 1 2 3 2 1 3 2 3 3 3 1 2 1 3 2 3 4 3 1 4 2 4 3 4 4 3 1 3 1 4 2 4 4 4 1 3 1 4 2 4 3 4 4 4 1 3 1 4 2 3 2 4 4 5 1 3 1 4 2 3 2 4 3 4 4 6 1 2 1 3 1 4 2 3 2 4 3 4 5 4 1 5 2 5 3 5 4 5 5 4 1 4 1 5 2 5 3 5 5 5 1 4 1 5 2 5 3 5 4 5 5 5 1 4 1 5 2 4 3 5 4 5 5 5 1 4 1 5 2 4 2 5 3 5 5 6 1 4 1 5 2 4 2 5 3 ...
output:
YES YES YES YES YES NO YES NO NO YES YES NO NO NO NO NO NO YES NO NO NO NO YES NO NO NO NO NO NO NO YES YES NO YES YES NO NO NO YES NO NO NO NO NO YES NO NO NO YES NO NO NO NO NO NO NO NO NO NO NO NO NO NO NO NO NO NO NO NO NO NO NO NO NO NO NO YES NO NO NO NO NO NO NO NO NO NO NO NO NO NO NO NO NO ...
result:
wrong answer expected YES, found NO [60th token]