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ID题目提交者结果用时内存语言文件大小提交时间测评时间
#101833#3846. Link-Cut TreeRegister_intAC ✓233ms8732kbC++141.4kb2023-05-01 12:43:162023-05-01 12:43:18

Judging History

你现在查看的是最新测评结果

  • [2023-08-10 23:21:45]
  • System Update: QOJ starts to keep a history of the judgings of all the submissions.
  • [2023-05-01 12:43:18]
  • 评测
  • 测评结果:AC
  • 用时:233ms
  • 内存:8732kb
  • [2023-05-01 12:43:16]
  • 提交

answer

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;

const int MAXN = 1e5 + 10;
const int mod = 998244353;

struct edge {
	int v, nxt;
} e[MAXN << 1];

int head[MAXN], tot = 1;

inline 
void add(int u, int v) {
	e[++tot] = { v, head[u] }, head[u] = tot;
}

int fa[MAXN];

int find(int k) {
	return k == fa[k] ? k : fa[k] = find(fa[k]);
}

inline 
bool merge(int u, int v) {
	return (u = find(u)) != (v = find(v)) && (fa[u] = v);
}

int pre[MAXN], id[MAXN];

int ans[MAXN], cnt, rt;

void init(int u) {
	if (!id[u]) rt = u;
	for (int i = head[u], v; i; i = e[i].nxt) {
		if ((i >> 1) == id[u]) continue; v = e[i].v;
		pre[v] = u, id[v] = i >> 1, init(v);
	}
}

inline 
void solve(int u) {
	for (cnt = 0; u != rt; u = pre[u]) ans[++cnt] = id[u];
}

inline 
void clear(int n) {
	for (int i = 1; i <= n; i++) head[i] = id[i] = pre[i] = 0; tot = 1;
}

int t, n, m, u[MAXN], v[MAXN];

int main() {
	for (scanf("%d", &t); t--; clear(n)) {
		scanf("%d%d", &n, &m), rt = 0;
		for (int i = 1; i <= m; i++) scanf("%d%d", &u[i], &v[i]);
		for (int i = 1; i <= n; i++) fa[i] = i;
		for (int i = 1; i <= m; i++) {
			if (!merge(u[i], v[i])) { init(u[i]), solve(v[i]), ans[++cnt] = i; break; }
			add(u[i], v[i]), add(v[i], u[i]);
		}
		if (!rt) { puts("-1"); continue; } sort(ans + 1, ans + cnt + 1);
		for (int i = 1; i <= cnt; i++) printf("%d%c", ans[i], " \n"[i == cnt]);
	}
}

详细

Test #1:

score: 100
Accepted
time: 0ms
memory: 3632kb

input:

2
6 8
1 2
2 3
5 6
3 4
2 5
5 4
5 1
4 2
4 2
1 2
4 3

output:

2 4 5 6
-1

result:

ok 2 lines

Test #2:

score: 0
Accepted
time: 117ms
memory: 7748kb

input:

1658
9 20
6 4
5 8
1 7
2 3
3 8
3 1
4 8
5 3
7 6
1 6
4 9
4 1
9 3
2 5
4 5
8 9
1 8
4 2
5 7
3 6
14 78
13 12
10 8
2 10
6 13
2 14
13 1
14 10
9 6
2 13
8 3
9 8
5 6
14 12
8 1
9 14
9 5
12 6
5 10
3 12
10 4
8 5
9 10
6 8
1 6
12 4
3 13
1 5
10 3
13 9
10 13
2 5
4 7
7 1
7 6
9 3
2 12
1 10
9 1
1 14
3 1
3 4
11 1
11 6
7 1...

output:

2 5 8
3 5 7
1 3 4
2 3 4
2 3 4 7 13
1 3 4 5 9
3 4 7 12
1 2 3
8 10 11
2 3 5 7 12 13 14 15 16
1 2 3 5
1 2 4
1 3 4
1 2 3
1 2 3
10 11 15
1 5 6
1 5 7
1 2 3 4
-1
1 3 6
-1
1 2 3 5
-1
-1
6 8 9 10 11 16
1 2 6
2 3 4
-1
-1
7 8 12 13 18
-1
1 4 8 12
3 5 10
4 6 8
1 2 3 4
3 5 6
5 8 10 15
4 6 8
-1
1 2 3 5 6
1 3 4
1 ...

result:

ok 1658 lines

Test #3:

score: 0
Accepted
time: 233ms
memory: 8732kb

input:

10
100000 100000
1 2
2 3
3 4
4 5
5 6
6 7
7 8
8 9
9 10
10 11
11 12
12 13
13 14
14 15
15 16
16 17
17 18
18 19
19 20
20 21
21 22
22 23
23 24
24 25
25 26
26 27
27 28
28 29
29 30
30 31
31 32
32 33
33 34
34 35
35 36
36 37
37 38
38 39
39 40
40 41
41 42
42 43
43 44
44 45
45 46
46 47
47 48
48 49
49 50
50 51
...

output:

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 ...

result:

ok 10 lines