oj.uz

Submission #1042424

# Submission time Handle Problem Language Result Execution time Memory
1042424 2024-08-03T04:24:43 Z sleepntsheep Inside information (BOI21_servers) C
62.5 / 100
 3500 ms 27220 KB 
/* WHAT IS EXTRA INFORAMZTION GTR RR */

#include <stdio.h>
#include <stdlib.h>

int max(int i, int j) { return i > j ? i : j; }
/*
 * 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)
 *
 * Should be able to optimize to O(N^1.5) using https://codeforces.com/blog/entry/71567?mobile=true&locale=en 
 */

#define N 120001
#define B 900

int n, q, pp[N], jj[N], dd[N], up[N], temp, inc[N], tin[N], tout[N], timer;

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) {
    tin[u] = timer++;
    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);
    }
    tout[u] = timer - 1;
}

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[2];
    int a, b;
} qq[N * 2];

int navigate(int u, int v) {
    int lb = -1, ub = eo[u];
    while (ub-lb>1){
        int md=lb+(ub-lb)/2;
        if(tin[eh[u][md]]<=tin[v])lb=md;
        else ub=md;
    }
    return eh[u][lb];
}

/* 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 = navigate(a, v), ua = navigate(a, u);

    ua = anc(u, dd[a] + 1);
    va = anc(v, 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 time, int root) {
    comp[u] = root;
    for (int j = 0; j < eo[u]; ++j)
        if (fh[u][j] <= time && comp[eh[u][j]] == -1)
            efs(eh[u][j], time, root);
}

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

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

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

int counted[N];

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

    q = n + q - 1;
    for (int j = 0, i = 0; i < q; ++i) {
        int a, b = 0;
        char *s = qq[i].type;

        scanf(" %s%d", s, &a);
        if (s[0] == 'S') {
            scanf("%d", &b);
            link(a, b, j++);
        } else if (s[0] == 'Q')
            scanf("%d", &b);

        qq[i].a = a, qq[i].b = 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[0] == 'S')
            ++j;

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

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

Compilation message

servers.c: In function 'pus_':
servers.c:32:26: warning: suggest parentheses around '-' in operand of '&' [-Wparentheses]
   32 |     else if (0 == (o & o - 1)) eh[i] = (int*)realloc(eh[i], 2 * o * sizeof **eh);
      |                        ~~^~~
servers.c: In function 'main':
servers.c:142:5: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
  142 |     scanf("%d%d", &n, &q);
      |     ^~~~~~~~~~~~~~~~~~~~~
servers.c:149:9: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
  149 |         scanf(" %s%d", s, &a);
      |         ^~~~~~~~~~~~~~~~~~~~~
servers.c:151:13: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
  151 |             scanf("%d", &b);
      |             ^~~~~~~~~~~~~~~
servers.c:154:13: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
  154 |             scanf("%d", &b);
      |             ^~~~~~~~~~~~~~~

Subtask #1
2.5 / 2.5

# Verdict Execution time Memory Grader output
1 Correct 21 ms 6744 KB Output is correct
2 Correct 38 ms 7248 KB Output is correct
3 Correct 36 ms 7256 KB Output is correct
4 Correct 53 ms 7260 KB Output is correct
5 Correct 56 ms 7504 KB Output is correct
6 Correct 36 ms 7260 KB Output is correct

Subtask #2
2.5 / 2.5

# Verdict Execution time Memory Grader output
1 Correct 21 ms 6744 KB Output is correct
2 Correct 38 ms 7248 KB Output is correct
3 Correct 36 ms 7256 KB Output is correct
4 Correct 53 ms 7260 KB Output is correct
5 Correct 56 ms 7504 KB Output is correct
6 Correct 36 ms 7260 KB Output is correct
7 Correct 23 ms 6896 KB Output is correct
8 Correct 139 ms 7020 KB Output is correct
9 Correct 90 ms 7248 KB Output is correct
10 Correct 290 ms 7252 KB Output is correct
11 Correct 164 ms 7504 KB Output is correct
12 Correct 135 ms 7384 KB Output is correct

Subtask #3
2.5 / 2.5

# Verdict Execution time Memory Grader output
1 Correct 23 ms 6748 KB Output is correct
2 Correct 356 ms 18520 KB Output is correct
3 Correct 364 ms 18512 KB Output is correct

Subtask #4
0 / 2.5

# Verdict Execution time Memory Grader output
1 Correct 23 ms 6748 KB Output is correct
2 Correct 356 ms 18520 KB Output is correct
3 Correct 364 ms 18512 KB Output is correct
4 Correct 28 ms 7060 KB Output is correct
5 Correct 1320 ms 19032 KB Output is correct
6 Execution timed out 3532 ms 19280 KB Time limit exceeded
7 Halted 0 ms 0 KB -

Subtask #5
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 22 ms 6908 KB Output is correct
2 Correct 700 ms 27072 KB Output is correct
3 Correct 1022 ms 27220 KB Output is correct
4 Correct 398 ms 26964 KB Output is correct

Subtask #6
0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 22 ms 6908 KB Output is correct
2 Correct 700 ms 27072 KB Output is correct
3 Correct 1022 ms 27220 KB Output is correct
4 Correct 398 ms 26964 KB Output is correct
5 Correct 24 ms 6748 KB Output is correct
6 Execution timed out 3538 ms 27216 KB Time limit exceeded
7 Halted 0 ms 0 KB -

Subtask #7
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 21 ms 6744 KB Output is correct
2 Correct 301 ms 17504 KB Output is correct
3 Correct 734 ms 17748 KB Output is correct

Subtask #8
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 21 ms 6744 KB Output is correct
2 Correct 301 ms 17504 KB Output is correct
3 Correct 734 ms 17748 KB Output is correct
4 Correct 24 ms 6744 KB Output is correct
5 Correct 809 ms 18000 KB Output is correct
6 Correct 1545 ms 18088 KB Output is correct

Subtask #9
12.5 / 12.5

# Verdict Execution time Memory Grader output
1 Correct 21 ms 6744 KB Output is correct
2 Correct 608 ms 26960 KB Output is correct
3 Correct 628 ms 26960 KB Output is correct
4 Correct 294 ms 27044 KB Output is correct
5 Correct 21 ms 6744 KB Output is correct
6 Correct 249 ms 17728 KB Output is correct
7 Correct 640 ms 17744 KB Output is correct
8 Correct 771 ms 18648 KB Output is correct
9 Correct 651 ms 18768 KB Output is correct
10 Correct 610 ms 21288 KB Output is correct
11 Correct 752 ms 20564 KB Output is correct

Subtask #10
0 / 12.5

# Verdict Execution time Memory Grader output
1 Correct 21 ms 6744 KB Output is correct
2 Correct 608 ms 26960 KB Output is correct
3 Correct 628 ms 26960 KB Output is correct
4 Correct 294 ms 27044 KB Output is correct
5 Correct 21 ms 6744 KB Output is correct
6 Correct 249 ms 17728 KB Output is correct
7 Correct 640 ms 17744 KB Output is correct
8 Correct 771 ms 18648 KB Output is correct
9 Correct 651 ms 18768 KB Output is correct
10 Correct 610 ms 21288 KB Output is correct
11 Correct 752 ms 20564 KB Output is correct
12 Correct 27 ms 6744 KB Output is correct
13 Execution timed out 3529 ms 27216 KB Time limit exceeded
14 Halted 0 ms 0 KB -

Subtask #11
17.5 / 17.5

# Verdict Execution time Memory Grader output
1 Correct 21 ms 6748 KB Output is correct
2 Correct 39 ms 7252 KB Output is correct
3 Correct 35 ms 7260 KB Output is correct
4 Correct 52 ms 7340 KB Output is correct
5 Correct 55 ms 7508 KB Output is correct
6 Correct 36 ms 7248 KB Output is correct
7 Correct 22 ms 7004 KB Output is correct
8 Correct 355 ms 18544 KB Output is correct
9 Correct 373 ms 18812 KB Output is correct
10 Correct 21 ms 6744 KB Output is correct
11 Correct 587 ms 26960 KB Output is correct
12 Correct 610 ms 26964 KB Output is correct
13 Correct 300 ms 27220 KB Output is correct
14 Correct 21 ms 6748 KB Output is correct
15 Correct 249 ms 17488 KB Output is correct
16 Correct 670 ms 17744 KB Output is correct
17 Correct 786 ms 18668 KB Output is correct
18 Correct 635 ms 18772 KB Output is correct
19 Correct 604 ms 21076 KB Output is correct
20 Correct 721 ms 20308 KB Output is correct
21 Correct 363 ms 18516 KB Output is correct
22 Correct 393 ms 18512 KB Output is correct
23 Correct 413 ms 19028 KB Output is correct
24 Correct 414 ms 19020 KB Output is correct
25 Correct 639 ms 20848 KB Output is correct
26 Correct 996 ms 17832 KB Output is correct
27 Correct 975 ms 18120 KB Output is correct

Subtask #12
0 / 17.5

# Verdict Execution time Memory Grader output
1 Correct 21 ms 6748 KB Output is correct
2 Correct 39 ms 7252 KB Output is correct
3 Correct 35 ms 7260 KB Output is correct
4 Correct 52 ms 7340 KB Output is correct
5 Correct 55 ms 7508 KB Output is correct
6 Correct 36 ms 7248 KB Output is correct
7 Correct 22 ms 7004 KB Output is correct
8 Correct 355 ms 18544 KB Output is correct
9 Correct 373 ms 18812 KB Output is correct
10 Correct 21 ms 6744 KB Output is correct
11 Correct 587 ms 26960 KB Output is correct
12 Correct 610 ms 26964 KB Output is correct
13 Correct 300 ms 27220 KB Output is correct
14 Correct 21 ms 6748 KB Output is correct
15 Correct 249 ms 17488 KB Output is correct
16 Correct 670 ms 17744 KB Output is correct
17 Correct 786 ms 18668 KB Output is correct
18 Correct 635 ms 18772 KB Output is correct
19 Correct 604 ms 21076 KB Output is correct
20 Correct 721 ms 20308 KB Output is correct
21 Correct 363 ms 18516 KB Output is correct
22 Correct 393 ms 18512 KB Output is correct
23 Correct 413 ms 19028 KB Output is correct
24 Correct 414 ms 19020 KB Output is correct
25 Correct 639 ms 20848 KB Output is correct
26 Correct 996 ms 17832 KB Output is correct
27 Correct 975 ms 18120 KB Output is correct
28 Correct 23 ms 6748 KB Output is correct
29 Correct 138 ms 7248 KB Output is correct
30 Correct 89 ms 7248 KB Output is correct
31 Correct 296 ms 7308 KB Output is correct
32 Correct 172 ms 7504 KB Output is correct
33 Correct 130 ms 7248 KB Output is correct
34 Correct 24 ms 6748 KB Output is correct
35 Correct 1326 ms 19152 KB Output is correct
36 Execution timed out 3527 ms 19296 KB Time limit exceeded
37 Halted 0 ms 0 KB -