#include <bits/stdc++.h>
using namespace std;
typedef pair<int, int> pii;
const int MAXN = 120000;
vector<pii> edges[MAXN];
pair<pii, int> queries[MAXN]; // start, end, time
int lca[MAXN][20];
pii lca_range[MAXN][20];
pii lca_range_rev[MAXN][20];
int depth[MAXN];
int n, k;
void dfs(int cur = 0, int p = -1) {
for (pii e: edges[cur]) {
int next = e.first;
if (next == p) continue;
depth[next] = depth[cur]+1;
lca[next][0] = cur;
lca_range[next][0] = pii(e.second, e.second);
lca_range_rev[next][0] = pii(e.second, e.second);
dfs(next, cur);
}
}
bool move(int &i, int pow, int &s) {
pii r = lca_range[i][pow];
if (s >= r.first) return 0;
s = r.second;
i = lca[i][pow];
return 1;
}
bool move_rev(int &i, int pow, int &e) {
pii r = lca_range_rev[i][pow];
if (r.second >= e || r.second == -1) return 0;
e = r.first;
i = lca[i][pow];
return 1;
}
void calc_lca(int i) {
int a = queries[i].first.first;
int b = queries[i].first.second;
int s = -1;
int e = queries[i].second;
int diff = depth[a]-depth[b];
int pow = 0;
while (diff > 0) {
if (diff & 1) {
bool bo = move(a, pow, s);
if (!bo) {
cout << "no\n";
return;
}
}
pow++;
diff /= 2;
}
diff = depth[b]-depth[a];
pow = 0;
while (diff > 0) {
if (diff & 1) {
bool bo = move_rev(b, pow, e);
if (!bo) {
cout << "no\n";
return;
}
}
pow++;
diff /= 2;
}
for (int i = 19; i >= 0; i--) {
if (lca[a][i] != lca[b][i]) {
bool bo = move(a, i, s);
if (!bo) {
cout << "no\n";
return;
}
bo = move_rev(b, i, e);
if (!bo) {
cout << "no\n";
return;
}
}
}
if (a != b) {
bool bo = move(a, 0, s);
if (!bo) {
cout << "no\n";
return;
}
bo = move_rev(b, 0, e);
if (!bo) {
cout << "no\n";
return;
}
}
if (s > e) {
cout << "no\n";
}
else cout << "yes\n";
}
int main() {
ios_base::sync_with_stdio(false); cin.tie(NULL);
cin >> n >> k;
int t = 0;
int p = 0;
for (int i = 0; i < n+k-1; i++) {
char c;
int a, b;
cin >> c >> a >> b;
a--; b--;
assert(c != 'C');
if (c == 'S') {
edges[a].push_back(pii(b, t));
edges[b].push_back(pii(a, t));
t++;
}
else {
queries[p] = pair<pii, int>(pii(b, a), t);
p++;
}
}
assert(t == n-1);
assert(p == k);
dfs();
lca_range[0][0] = pii(-1, -1);
lca_range_rev[0][0] = pii(-1, -1);
for (int i = 1; i < 20; i++) {
for (int j = 0; j < n; j++) {
lca[j][i] = lca[lca[j][i-1]][i-1];
pii r1 = lca_range[j][i-1];
pii r2 = lca_range[lca[j][i-1]][i-1];
if (r1.second >= 0 && r1.second < r2.first) lca_range[j][i] = pii(r1.first, r2.second);
else lca_range[j][i] = pii(-1, -1);
r1 = lca_range_rev[j][i-1];
r2 = lca_range_rev[lca[j][i-1]][i-1];
if (r2.second >= 0 && r2.second < r1.first) lca_range_rev[j][i] = pii(r2.first, r1.second);
else lca_range_rev[j][i] = pii(-1, -1);
}
}
for (int i = 0; i < k; i++) {
calc_lca(i);
}
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
22 ms |
4848 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
22 ms |
4848 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
22 ms |
4948 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
22 ms |
4948 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
19 ms |
4916 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
19 ms |
4916 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
22 ms |
4880 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
22 ms |
4880 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
21 ms |
4872 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
21 ms |
4872 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
22 ms |
4936 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
22 ms |
4936 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |