| # |
Submission time |
Handle |
Problem |
Language |
Result |
Execution time |
Memory |
| 503744 |
2022-01-08T20:29:52 Z |
rainboy |
Wells (CEOI21_wells) |
C |
|
1 ms |
284 KB |
/* https://hsin.hr/ceoi/competition/ceoi2021_day2_editorial.pdf */
#include <stdio.h>
#define N 300
#define MD 1000000007
int min(int a, int b) { return a < b ? a : b; }
int max(int a, int b) { return a > b ? a : b; }
int pp2[N + 1];
void init() {
int i;
pp2[0] = 1;
for (i = 1; i <= N; i++)
pp2[i] = pp2[i - 1] * 2 % MD;
}
int mem[(N - 1) * 2], *ptr = mem;
int *ej[N], eo[N], pp[N], cc[N], n, k; char type[N];
int i_, l;
void dfs1(int p, int i, int d) {
int o;
pp[i] = p;
d++;
if (l < d)
l = d, i_ = i;
for (o = eo[i]; o--; ) {
int j = ej[i][o];
if (j != p)
dfs1(i, j, d);
}
}
char path[N];
int gg[N], dd[N], hh[N];
void dfs2(int p, int i, int g, int d) {
int o;
gg[i] = g, dd[i] = d, hh[i] = 0;
for (o = eo[i]; o--; ) {
int j = ej[i][o];
if (j != p && !path[j]) {
dfs2(i, j, g, d + 1);
hh[i] = max(hh[i], hh[j] + 1);
}
}
}
int contains(int a, int b, int r) {
a %= r, b %= r;
return a <= b ? a <= r && r <= b : a <= r || r <= b;
}
int check_(int p, int i, int d, int c) {
int o;
if (type[i] != 1)
return 1;
if (--d == 0)
return c == 1;
for (o = eo[i]; o--; ) {
int j = ej[i][o];
if (j != p && !check_(i, j, d, c))
return 0;
}
return 1;
}
int check() {
int i;
for (i = 0; i < n; i++)
if (!check_(-1, i, k, 0))
return 0;
return 1;
}
int main() {
static int uu[N - 1], vv[N - 1], ii[N];
int g, h, i, j, u, v, d, r, yes;
init();
scanf("%d%d", &n, &k);
if (k == 2) {
printf("YES\n");
printf("2\n");
return 0;
}
for (h = 0; h < n - 1; h++) {
scanf("%d%d", &i, &j), i--, j--;
uu[h] = i, vv[h] = j;
eo[i]++, eo[j]++;
}
for (i = 0; i < n; i++) {
ej[i] = ptr, ptr += eo[i];
eo[i] = 0;
}
for (h = 0; h < n - 1; h++) {
i = uu[h], j = vv[h];
ej[i][eo[i]++] = j, ej[j][eo[j]++] = i;
}
i_ = -1, l = -1, dfs1(-1, 0, 0), u = i_;
i_ = -1, l = -1, dfs1(-1, u, 0), v = i_;
for (i = v, d = l - 1; i != u; i = pp[i], d--)
path[ii[d] = i] = 1;
path[ii[0] = u] = 1;
if (l < k) {
printf("YES\n");
printf("%d\n", pp2[n]);
return 0;
}
for (g = 0; g < l; g++)
dfs2(-1, ii[g], g, 0);
for (i = 0; i < n; i++) {
g = gg[i];
if (max(g, l - 1 - g) + dd[i] + hh[i] < k - 1)
type[i] = -1;
else if (min(g, l - 1 - g) + dd[i] + hh[i] >= k - 1)
type[i] = 1;
else
type[i] = 0;
}
yes = 0;
for (r = 0; r < k; r++) {
int gl, gr, good;
gl = r, gr = (l - 1 - r) / k * k + r;
good = 1;
for (g = 0; g < gl; g++) {
i = ii[g], h = k - 1 - (gl - g);
if (g + h >= k && hh[i] >= h) {
good = 0;
break;
}
}
if (!good)
continue;
for (g = gr + 1; g < l; g++) {
i = ii[g], h = k - 1 - (g - gr);
if (l - 1 - g + h >= k && hh[i] >= h) {
good = 0;
break;
}
}
if (!good)
continue;
for (i = 0; i < n; i++) {
g = gg[i], d = dd[i];
if (path[i])
cc[i] = g % k == r ? 1 : 0;
else if (type[i] == 1) {
int cl = g >= gl ? ((g + d) % k == r ? 1 : 0) : -1;
int cr = g <= gr ? ((g - d % k + k) % k == r ? 1 : 0) : -1;
if (cl != -1 && cr != -1) {
if (cl != cr) {
good = 0;
break;
}
cc[i] = cl;
} else
cc[i] = cl != -1 ? cl : cr;
}
}
if (!good)
continue;
if (check())
yes = 1;
}
if (yes)
printf("YES\n");
else
printf("NO\n");
printf("0\n");
return 0;
}
Compilation message
wells.c: In function 'main':
wells.c:92:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
92 | scanf("%d%d", &n, &k);
| ^~~~~~~~~~~~~~~~~~~~~
wells.c:99:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
99 | scanf("%d%d", &i, &j), i--, j--;
| ^~~~~~~~~~~~~~~~~~~~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
1 ms |
284 KB |
Output is correct |
| 2 |
Partially correct |
1 ms |
204 KB |
Output is partially correct |
| 3 |
Partially correct |
1 ms |
204 KB |
Output is partially correct |
| 4 |
Incorrect |
0 ms |
204 KB |
Output isn't correct |
| 5 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
1 ms |
284 KB |
Output is correct |
| 2 |
Partially correct |
1 ms |
204 KB |
Output is partially correct |
| 3 |
Partially correct |
1 ms |
204 KB |
Output is partially correct |
| 4 |
Incorrect |
0 ms |
204 KB |
Output isn't correct |
| 5 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
1 ms |
284 KB |
Output is correct |
| 2 |
Partially correct |
1 ms |
204 KB |
Output is partially correct |
| 3 |
Partially correct |
1 ms |
204 KB |
Output is partially correct |
| 4 |
Incorrect |
0 ms |
204 KB |
Output isn't correct |
| 5 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
1 ms |
284 KB |
Output is correct |
| 2 |
Partially correct |
1 ms |
204 KB |
Output is partially correct |
| 3 |
Partially correct |
1 ms |
204 KB |
Output is partially correct |
| 4 |
Incorrect |
0 ms |
204 KB |
Output isn't correct |
| 5 |
Halted |
0 ms |
0 KB |
- |
