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Submission #1042388

# Submission time Handle Problem Language Result Execution time Memory
1042388 2024-08-03T03:26:21 Z sleepntsheep Inside information (BOI21_servers) C
50 / 100
 3500 ms 30852 KB 
#include <stdio.h>
#include <stdlib.h>

/*
 * For "Q" queries, use LCA + prefix sum on tree ~ 3O(lgn) [for finding lca and almost-lca]
 *
 *
 * Every B queries of any type, do naive dp on tree (reverse edge order)
 * to find answer for "C" queries  ~ O(n)
 *
 * On "C" queries, use cached answer from above and count all edges that appeared after that (by "Q")
 * ~ O(B lgn)
 *
 *
 * Time complexity = O(N^2 / B) + O(N lgn) + O(N B lgn)
 *
 * Let B = sqrt(N / lgN)
 */

#define N 120001
#define B 1600


int n, q, pp[N], jj[N], dd[N], up[N], temp, inc[N], map_time[N];

void pus_(int **eh, int *eo, int i, int j) {
    int o = eo[i]++;
    if (0 == o) eh[i] = (int*)malloc(2 * sizeof **eh);
    else if (0 == (o & o - 1)) eh[i] = (int*)realloc(eh[i], 2 * o * sizeof **eh);
    eh[i][o] = j;
}

int *eh[N], *fh[N], eo[N];

void link(int u, int v, int w) {
    pus_(eh, eo, u, v);
    --eo[u];
    pus_(fh, eo, u, w);
    pus_(eh, eo, v, u);
    --eo[v];
    pus_(fh, eo, v, w);
}

void dfs(int u, int p) {
    inc[u] = (up[u] > up[p]) + inc[p];
    for (int j = 0; j < eo[u]; ++j) if (eh[u][j] != p) {
        int v = eh[u][j];
        dd[v] = dd[u] + 1;
        pp[v] = u;
        jj[v] = (dd[u] - dd[jj[u]] == dd[jj[u]] - dd[jj[jj[u]]]) ? jj[jj[u]]: u;

        up[v] = fh[u][j];
        dfs(v, u);
    }
}

int lca(int u, int v) {
    while (dd[u] != dd[v]) {
        if (dd[u] < dd[v]) temp = u, u = v, v = temp;
        u = (dd[jj[u]] >= dd[v]) ? jj[u] : pp[u];
    }
    while (u != v)
        if (jj[u] != jj[v]) u = jj[u], v = jj[v];
        else u = pp[u], v = pp[v];
    return u;
}

int anc(int u, int dep) {
    while (dd[u] > dep)
        u = (dd[jj[u]] >= dep) ? jj[u] : pp[u];
    return u;
}

struct Query {
    char type;
    int a, b;
    int ans;
} qq[N * 2];

/* u = data node, v = ask node */
int query_yesno(int u, int v, int time) {
    if (u == v) return 1;
    int a = lca(u, v);
    int va = anc(v, dd[a] + 1);
    int ua = anc(u, dd[a] + 1);

    if (u == a)
        return inc[v] - inc[va] == dd[v] - dd[va] && up[v] <= time;
    if (v == a)
        return inc[u] - inc[ua] == 0 && up[ua] <= time;

    return (dd[v] - dd[va] == inc[v] - inc[va]) && (inc[u] - inc[ua] == 0)
        && up[va] > up[ua] && up[v] <= time;
}

int dp[N], comp[N];

void efs(int u, int p, int time, int root) {
    comp[u] = root;
    for (int j = 0; j < eo[u]; ++j)
        if (eh[u][j] != p && fh[u][j] <= time && comp[eh[u][j]] == -1)
            efs(eh[u][j], u, time, root);
}

void build(int ii, int tme) {
    for (int i = 1; i <= n; ++i)
        dp[i] = 1, comp[i] = -1;

    for (int i = ii; i >= 0; --i) {
        if (qq[i].type != 'S')
            continue;

        int x = dp[qq[i].a], y = dp[qq[i].b];
        dp[qq[i].a] += y;
        dp[qq[i].b] += x;
    }

    for (int i = 1; i <= n; ++i)
        if (comp[i] == -1)
            efs(i, i, tme, i);
}

int counted[N];

int main() {
    scanf("%d%d", &n, &q);

    q = n + q - 1;
    for (int j = 0, i = 0; i < q; ++i) {
        char c;
        int a, b;
        scanf(" %c%d", &c, &a);
        if (c == 'S') {
            scanf("%d", &b);
            link(a, b, j++);
            map_time[j - 1] = i;
        } else if (c == 'Q')
            scanf("%d", &b);

        qq[i] = (struct Query){c, a, b};
    }

    up[1] = 1e9;
    pp[1] = jj[1] = 1;
    dfs(1, 1);

    build(-1, -1);
    int at = 0;

    for (int j = 0, i = 0; i < q; ++i) {
        if (qq[i].type == 'S') {
            ++j;
        }
        else if (qq[i].type == 'Q') {
            puts(query_yesno(qq[i].b, qq[i].a, j - 1) ? "yes": "no");
        } else {
            int focus = qq[i].a;
            int addition = 0;
            for (int k = at; k < i; ++k)
                if (qq[k].type == 'S') {
                    int a = qq[k].a, b = qq[k].b;

                    if (counted[a] != i + 1 &&
                            comp[a] != comp[focus] && query_yesno(focus, a, j - 1))
                        ++addition, counted[a] = i + 1;
                    if (counted[b] != i + 1 && 
                            comp[b] != comp[focus] && query_yesno(focus, b, j - 1))
                        ++addition, counted[b] = i + 1;
                }
            printf("%d\n", dp[focus] + addition);
        }

        if (i % B == 0) {
            build(i, j);
            at = i + 1;
        }
    }
}

Compilation message

servers.c: In function 'pus_':
servers.c:30:26: warning: suggest parentheses around '-' in operand of '&' [-Wparentheses]
   30 |     else if (0 == (o & o - 1)) eh[i] = (int*)realloc(eh[i], 2 * o * sizeof **eh);
      |                        ~~^~~
servers.c: In function 'main':
servers.c:127:5: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
  127 |     scanf("%d%d", &n, &q);
      |     ^~~~~~~~~~~~~~~~~~~~~
servers.c:133:9: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
  133 |         scanf(" %c%d", &c, &a);
      |         ^~~~~~~~~~~~~~~~~~~~~~
servers.c:135:13: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
  135 |             scanf("%d", &b);
      |             ^~~~~~~~~~~~~~~
servers.c:139:13: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
  139 |             scanf("%d", &b);
      |             ^~~~~~~~~~~~~~~

Subtask #1
2.5 / 2.5

# Verdict Execution time Memory Grader output
1 Correct 19 ms 3420 KB Output is correct
2 Correct 33 ms 4444 KB Output is correct
3 Correct 27 ms 4688 KB Output is correct
4 Correct 56 ms 4640 KB Output is correct
5 Correct 46 ms 4688 KB Output is correct
6 Correct 25 ms 4688 KB Output is correct

Subtask #2
0 / 2.5

# Verdict Execution time Memory Grader output
1 Correct 19 ms 3420 KB Output is correct
2 Correct 33 ms 4444 KB Output is correct
3 Correct 27 ms 4688 KB Output is correct
4 Correct 56 ms 4640 KB Output is correct
5 Correct 46 ms 4688 KB Output is correct
6 Correct 25 ms 4688 KB Output is correct
7 Correct 22 ms 3416 KB Output is correct
8 Incorrect 145 ms 4180 KB Extra information in the output file
9 Halted 0 ms 0 KB -

Subtask #3
2.5 / 2.5

# Verdict Execution time Memory Grader output
1 Correct 18 ms 3616 KB Output is correct
2 Correct 238 ms 21796 KB Output is correct
3 Correct 227 ms 21892 KB Output is correct

Subtask #4
0 / 2.5

# Verdict Execution time Memory Grader output
1 Correct 18 ms 3616 KB Output is correct
2 Correct 238 ms 21796 KB Output is correct
3 Correct 227 ms 21892 KB Output is correct
4 Correct 20 ms 3416 KB Output is correct
5 Incorrect 375 ms 22352 KB Extra information in the output file
6 Halted 0 ms 0 KB -

Subtask #5
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 21 ms 3420 KB Output is correct
2 Correct 401 ms 30700 KB Output is correct
3 Correct 398 ms 30804 KB Output is correct
4 Correct 210 ms 30800 KB Output is correct

Subtask #6
0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 21 ms 3420 KB Output is correct
2 Correct 401 ms 30700 KB Output is correct
3 Correct 398 ms 30804 KB Output is correct
4 Correct 210 ms 30800 KB Output is correct
5 Correct 26 ms 3672 KB Output is correct
6 Execution timed out 3544 ms 30572 KB Time limit exceeded
7 Halted 0 ms 0 KB -

Subtask #7
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 19 ms 3420 KB Output is correct
2 Correct 171 ms 21448 KB Output is correct
3 Correct 412 ms 21588 KB Output is correct

Subtask #8
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 19 ms 3420 KB Output is correct
2 Correct 171 ms 21448 KB Output is correct
3 Correct 412 ms 21588 KB Output is correct
4 Correct 22 ms 3416 KB Output is correct
5 Incorrect 784 ms 21488 KB Extra information in the output file
6 Halted 0 ms 0 KB -

Subtask #9
12.5 / 12.5

# Verdict Execution time Memory Grader output
1 Correct 20 ms 3420 KB Output is correct
2 Correct 384 ms 30764 KB Output is correct
3 Correct 399 ms 30712 KB Output is correct
4 Correct 257 ms 30700 KB Output is correct
5 Correct 19 ms 3420 KB Output is correct
6 Correct 161 ms 21332 KB Output is correct
7 Correct 426 ms 21464 KB Output is correct
8 Correct 523 ms 22432 KB Output is correct
9 Correct 426 ms 22356 KB Output is correct
10 Correct 434 ms 24916 KB Output is correct
11 Correct 529 ms 24144 KB Output is correct

Subtask #10
0 / 12.5

# Verdict Execution time Memory Grader output
1 Correct 20 ms 3420 KB Output is correct
2 Correct 384 ms 30764 KB Output is correct
3 Correct 399 ms 30712 KB Output is correct
4 Correct 257 ms 30700 KB Output is correct
5 Correct 19 ms 3420 KB Output is correct
6 Correct 161 ms 21332 KB Output is correct
7 Correct 426 ms 21464 KB Output is correct
8 Correct 523 ms 22432 KB Output is correct
9 Correct 426 ms 22356 KB Output is correct
10 Correct 434 ms 24916 KB Output is correct
11 Correct 529 ms 24144 KB Output is correct
12 Correct 22 ms 3420 KB Output is correct
13 Execution timed out 3536 ms 30496 KB Time limit exceeded
14 Halted 0 ms 0 KB -

Subtask #11
17.5 / 17.5

# Verdict Execution time Memory Grader output
1 Correct 20 ms 3420 KB Output is correct
2 Correct 33 ms 4440 KB Output is correct
3 Correct 26 ms 4692 KB Output is correct
4 Correct 48 ms 4692 KB Output is correct
5 Correct 51 ms 4692 KB Output is correct
6 Correct 24 ms 4440 KB Output is correct
7 Correct 18 ms 3416 KB Output is correct
8 Correct 223 ms 21868 KB Output is correct
9 Correct 244 ms 21844 KB Output is correct
10 Correct 20 ms 3504 KB Output is correct
11 Correct 399 ms 30852 KB Output is correct
12 Correct 364 ms 30768 KB Output is correct
13 Correct 221 ms 30800 KB Output is correct
14 Correct 19 ms 3420 KB Output is correct
15 Correct 175 ms 21232 KB Output is correct
16 Correct 411 ms 21328 KB Output is correct
17 Correct 510 ms 22356 KB Output is correct
18 Correct 415 ms 22356 KB Output is correct
19 Correct 412 ms 25168 KB Output is correct
20 Correct 526 ms 24320 KB Output is correct
21 Correct 231 ms 22492 KB Output is correct
22 Correct 245 ms 22680 KB Output is correct
23 Correct 295 ms 22756 KB Output is correct
24 Correct 269 ms 22772 KB Output is correct
25 Correct 396 ms 24668 KB Output is correct
26 Correct 583 ms 21700 KB Output is correct
27 Correct 608 ms 21724 KB Output is correct

Subtask #12
0 / 17.5

# Verdict Execution time Memory Grader output
1 Correct 20 ms 3420 KB Output is correct
2 Correct 33 ms 4440 KB Output is correct
3 Correct 26 ms 4692 KB Output is correct
4 Correct 48 ms 4692 KB Output is correct
5 Correct 51 ms 4692 KB Output is correct
6 Correct 24 ms 4440 KB Output is correct
7 Correct 18 ms 3416 KB Output is correct
8 Correct 223 ms 21868 KB Output is correct
9 Correct 244 ms 21844 KB Output is correct
10 Correct 20 ms 3504 KB Output is correct
11 Correct 399 ms 30852 KB Output is correct
12 Correct 364 ms 30768 KB Output is correct
13 Correct 221 ms 30800 KB Output is correct
14 Correct 19 ms 3420 KB Output is correct
15 Correct 175 ms 21232 KB Output is correct
16 Correct 411 ms 21328 KB Output is correct
17 Correct 510 ms 22356 KB Output is correct
18 Correct 415 ms 22356 KB Output is correct
19 Correct 412 ms 25168 KB Output is correct
20 Correct 526 ms 24320 KB Output is correct
21 Correct 231 ms 22492 KB Output is correct
22 Correct 245 ms 22680 KB Output is correct
23 Correct 295 ms 22756 KB Output is correct
24 Correct 269 ms 22772 KB Output is correct
25 Correct 396 ms 24668 KB Output is correct
26 Correct 583 ms 21700 KB Output is correct
27 Correct 608 ms 21724 KB Output is correct
28 Correct 21 ms 3524 KB Output is correct
29 Incorrect 146 ms 4168 KB Extra information in the output file
30 Halted 0 ms 0 KB -