#include <stdio.h>
#include <stdlib.h>
#define N 200000
int *ej[N], eo[N], *ej_[N], eo_[N];
void append(int **ej, int *eo, int i, int j) {
int o = eo[i]++;
if (o >= 2 && (o & o - 1) == 0)
ej[i] = (int *) realloc(ej[i], o * 2 * sizeof *ej[i]);
ej[i][o] = j;
}
int pp[N], dd[N], qq[N], sz[N];
void dfs1(int p, int i, int d) {
int o, j_;
pp[i] = p, dd[i] = d, sz[i] = 1, j_ = -1;
for (o = eo[i]; o--; ) {
int j = ej[i][o];
if (j != p) {
dfs1(i, j, d + 1);
sz[i] += sz[j];
if (j_ == -1 || sz[j_] < sz[j])
j_ = j;
}
}
qq[i] = j_;
}
void dfs2(int p, int i, int q) {
int o, j_;
j_ = qq[i], qq[i] = q;
if (j_ == -1)
dfs2(i, j_, q);
for (o = eo[i]; o--; ) {
int j = ej[i][o];
if (j != p && j != j_)
dfs2(i, j, j);
}
}
int lca(int i, int j) {
while (qq[i] != qq[j])
if (dd[qq[i]] > dd[qq[j]])
i = pp[qq[i]];
else
j = pp[qq[j]];
return dd[i] < dd[j] ? i : j;
}
int dist(int i, int j) {
return dd[i] + dd[j] - dd[lca(i, j)] * 2;
}
int main() {
static char used[N];
static int ans[N + 1];
int n, h, i, j, k, u, v, o, d;
scanf("%d", &n);
for (i = 0; i < n; i++)
ej[i] = (int *) malloc(2 * sizeof *ej[i]);
for (h = 0; h < n - 1; h++) {
scanf("%d%d", &i, &j), i--, j--;
append(ej, eo, i, j), append(ej, eo, j, i);
}
dfs1(-1, 0, 0), dfs2(-1, 0, 0);
for (i = 0; i < n; i++)
ej_[i] = (int *) malloc(2 * sizeof *ej_[i]);
for (i = 1; i < n; i++)
if (sz[i] < n - sz[i])
used[i] = 1, append(ej_, eo_, sz[i], i);
else if (sz[i] > n - sz[i])
used[pp[i]] = 1, append(ej_, eo_, n - sz[i], pp[i]);
u = v = -1;
for (i = 0; i < n; i++)
if (!used[i]) {
if (u == -1)
u = i;
else
v = i;
}
if (v == -1)
v = u;
d = dist(u, v);
for (k = n; k >= 1; k--)
if (k % 2 != 0)
ans[k] = 1;
else {
for (o = eo_[k / 2]; o--; ) {
int du, dv;
j = ej_[k / 2][o];
du = dist(u, j), dv = dist(v, j);
if (du >= d && du >= dv)
v = j, d = du;
else if (dv >= d && dv >= du)
u = j, d = dv;
}
ans[k] = d + 1;
}
for (k = 1; k <= n; k++)
printf("%d\n", ans[k]);
return 0;
}
Compilation message
meetings2.c: In function 'append':
meetings2.c:11:23: warning: suggest parentheses around '-' in operand of '&' [-Wparentheses]
11 | if (o >= 2 && (o & o - 1) == 0)
| ~~^~~
meetings2.c: In function 'main':
meetings2.c:67:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
67 | scanf("%d", &n);
| ^~~~~~~~~~~~~~~
meetings2.c:71:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
71 | scanf("%d%d", &i, &j), i--, j--;
| ^~~~~~~~~~~~~~~~~~~~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
0 ms |
212 KB |
Output is correct |
| 2 |
Correct |
0 ms |
212 KB |
Output is correct |
| 3 |
Execution timed out |
4041 ms |
212 KB |
Time limit exceeded |
| 4 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
0 ms |
212 KB |
Output is correct |
| 2 |
Correct |
0 ms |
212 KB |
Output is correct |
| 3 |
Execution timed out |
4041 ms |
212 KB |
Time limit exceeded |
| 4 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
0 ms |
212 KB |
Output is correct |
| 2 |
Correct |
0 ms |
212 KB |
Output is correct |
| 3 |
Execution timed out |
4041 ms |
212 KB |
Time limit exceeded |
| 4 |
Halted |
0 ms |
0 KB |
- |
