#include <stdio.h>
#include <stdlib.h>
#define N 200000
#define INF 0x3f3f3f3f
int max(int a, int b) { return a > b ? a : b; }
unsigned int X = 12345;
int rand_() {
return (X *= 3) >> 1;
}
int *ej[N], eo[N];
void append(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 ta[N], tb[N];
void dfs(int i) {
static int time;
int o;
ta[i] = time++;
for (o = eo[i]; o--; ) {
int j = ej[i][o];
dfs(j);
}
tb[i] = time;
}
void sort(int *ii, int l, int r) {
while (l < r) {
int i = l, j = l, k = r, i_ = ii[l + rand_() % (r - l)], tmp;
while (j < k)
if (tb[ii[j]] == tb[i_])
j++;
else if (tb[ii[j]] < tb[i_]) {
tmp = ii[i], ii[i] = ii[j], ii[j] = tmp;
i++, j++;
} else {
k--;
tmp = ii[j], ii[j] = ii[k], ii[k] = tmp;
}
sort(ii, l, i);
l = k;
}
}
int main() {
static int ww[N], ii[N], hh[N], dp[N];
int n, k, h, h_, i, p, r, lower, upper;
scanf("%d%d", &n, &k);
for (i = 0; i < n; i++)
ej[i] = (int *) malloc(2 * sizeof *ej[i]);
r = -1;
for (i = 0; i < n; i++) {
scanf("%d%d", &p, &ww[i]), p--;
if (p >= 0)
append(p, i);
else
r = i;
}
dfs(r);
for (i = 0; i < n; i++)
ii[i] = i;
sort(ii, 0, n);
for (h = 0; h < n; h++) {
lower = -1, upper = i;
while (upper - lower > 1) {
h_ = (lower + upper) / 2;
if (tb[ii[h_]] <= ta[ii[h]])
lower = h_;
else
upper = h_;
}
hh[h] = lower;
}
for (h = 0; h < n; h++)
dp[h] = ww[ii[h]];
for (h = 1; h < n; h++)
dp[h] = max(dp[h], dp[h - 1]);
while (--k) {
for (h = n - 1; h >= 0; h--)
dp[h] = hh[h] == -1 || dp[hh[h]] == -INF ? -INF : dp[hh[h]] + ww[ii[h]];
for (h = 1; h < n; h++)
dp[h] = max(dp[h], dp[h - 1]);
}
printf("%d\n", dp[n - 1]);
return 0;
}
Compilation message
biochips.c: In function 'append':
biochips.c:20:23: warning: suggest parentheses around '-' in operand of '&' [-Wparentheses]
20 | if (o >= 2 && (o & o - 1) == 0)
| ~~^~~
biochips.c: In function 'main':
biochips.c:63:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
63 | scanf("%d%d", &n, &k);
| ^~~~~~~~~~~~~~~~~~~~~
biochips.c:68:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
68 | scanf("%d%d", &p, &ww[i]), p--;
| ^~~~~~~~~~~~~~~~~~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
212 KB |
Output is correct |
2 |
Correct |
1 ms |
212 KB |
Output is correct |
3 |
Correct |
1 ms |
340 KB |
Output is correct |
4 |
Correct |
7 ms |
944 KB |
Output is correct |
5 |
Correct |
10 ms |
1076 KB |
Output is correct |
6 |
Correct |
11 ms |
1072 KB |
Output is correct |
7 |
Correct |
319 ms |
12700 KB |
Output is correct |
8 |
Correct |
318 ms |
12620 KB |
Output is correct |
9 |
Correct |
443 ms |
13980 KB |
Output is correct |
10 |
Correct |
593 ms |
15328 KB |
Output is correct |