oj.uz

Submission #1042492

# Submission time Handle Problem Language Result Execution time Memory
1042492 2024-08-03T05:40:03 Z sleepntsheep Inside information (BOI21_servers) C
80 / 100
 3500 ms 32340 KB 
#include <string.h>
#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], dd[N], up[N], temp, inc[N],
    tin[N], tout[N], timer, hld[N], ds[N], sz[N];

int ds_find(int i) {
    return ds[i] == i ? i : (ds[i] = ds_find(ds[i]));
}

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) {
    sz[u] = 1;
    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;
        up[v] = fh[u][j];
        dfs(v, u);
        sz[u] += sz[v];
    }

    for (int j = 0; j < eo[u]; ++j) if (eh[u][j] == p) {
        int ww = fh[u][j];
        for (int k = j + 1; k < eo[u]; ++k)
            eh[u][k - 1] = eh[u][k], fh[u][k - 1] = fh[u][k];
        --eo[u];
        eh[u][eo[u]] = p;
        fh[u][eo[u]] = ww;
        break;
    }

    for (int j = 0; j < eo[u]; ++j) {
        int v = eh[u][j];
        if (sz[v] > sz[eh[u][0]]) {
            temp = eh[u][0], eh[u][0] = v, eh[u][j] = temp;
            temp = fh[u][0], fh[u][0] = fh[u][j], fh[u][j] = temp;
        }
    }
}

void efs(int u, int hd) {
    tin[u] = timer++;
    hld[u] = hd;
    if (eo[u])
        efs(eh[u][0], hd);
    for (int j = 1; j < eo[u]; ++j)
        efs(eh[u][j], eh[u][j]);
    tout[u] = timer - 1;
}

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

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, ua;

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

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

int dp[N];

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

    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] = 1;
    dfs(1, 1);
    efs(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) {
            for (int k = at; k <= i; ++k)
                if (qq[k].type[0] == 'S')
                    ds[ds_find(qq[k].a)] = qq[k].b;
            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 &&
                            ds[a] != ds[focus] && query_yesno(focus, a, j - 1))
                        ++addition, counted[a] = i + 1;
                    if (counted[b] != i + 1 && 
                            ds[b] != ds[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:36:26: warning: suggest parentheses around '-' in operand of '&' [-Wparentheses]
   36 |     else if (0 == (o & o - 1)) eh[i] = (int*)realloc(eh[i], 2 * o * sizeof **eh);
      |                        ~~^~~
servers.c: In function 'main':
servers.c:157:5: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
  157 |     scanf("%d%d", &n, &q);
      |     ^~~~~~~~~~~~~~~~~~~~~
servers.c:166:9: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
  166 |         scanf(" %s%d", s, &a);
      |         ^~~~~~~~~~~~~~~~~~~~~
servers.c:168:13: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
  168 |             scanf("%d", &b);
      |             ^~~~~~~~~~~~~~~
servers.c:171:13: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
  171 |             scanf("%d", &b);
      |             ^~~~~~~~~~~~~~~

Subtask #1
2.5 / 2.5

# Verdict Execution time Memory Grader output
1 Correct 20 ms 7004 KB Output is correct
2 Correct 38 ms 7508 KB Output is correct
3 Correct 34 ms 7644 KB Output is correct
4 Correct 30 ms 7516 KB Output is correct
5 Correct 27 ms 7772 KB Output is correct
6 Correct 37 ms 7448 KB Output is correct

Subtask #2
2.5 / 2.5

# Verdict Execution time Memory Grader output
1 Correct 20 ms 7004 KB Output is correct
2 Correct 38 ms 7508 KB Output is correct
3 Correct 34 ms 7644 KB Output is correct
4 Correct 30 ms 7516 KB Output is correct
5 Correct 27 ms 7772 KB Output is correct
6 Correct 37 ms 7448 KB Output is correct
7 Correct 22 ms 7004 KB Output is correct
8 Correct 108 ms 7332 KB Output is correct
9 Correct 78 ms 7504 KB Output is correct
10 Correct 79 ms 7436 KB Output is correct
11 Correct 40 ms 7764 KB Output is correct
12 Correct 122 ms 7668 KB Output is correct

Subtask #3
2.5 / 2.5

# Verdict Execution time Memory Grader output
1 Correct 29 ms 6992 KB Output is correct
2 Correct 210 ms 19084 KB Output is correct
3 Correct 214 ms 19052 KB Output is correct

Subtask #4
0 / 2.5

# Verdict Execution time Memory Grader output
1 Correct 29 ms 6992 KB Output is correct
2 Correct 210 ms 19084 KB Output is correct
3 Correct 214 ms 19052 KB Output is correct
4 Correct 24 ms 7096 KB Output is correct
5 Correct 1099 ms 19464 KB Output is correct
6 Correct 2154 ms 19908 KB Output is correct
7 Execution timed out 3530 ms 19544 KB Time limit exceeded
8 Halted 0 ms 0 KB -

Subtask #5
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 20 ms 7004 KB Output is correct
2 Correct 196 ms 29264 KB Output is correct
3 Correct 170 ms 29388 KB Output is correct
4 Correct 106 ms 29428 KB Output is correct

Subtask #6
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 20 ms 7004 KB Output is correct
2 Correct 196 ms 29264 KB Output is correct
3 Correct 170 ms 29388 KB Output is correct
4 Correct 106 ms 29428 KB Output is correct
5 Correct 29 ms 7056 KB Output is correct
6 Correct 456 ms 29780 KB Output is correct
7 Correct 273 ms 29780 KB Output is correct
8 Correct 654 ms 29520 KB Output is correct
9 Correct 680 ms 32324 KB Output is correct

Subtask #7
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 20 ms 7004 KB Output is correct
2 Correct 119 ms 18004 KB Output is correct
3 Correct 197 ms 18096 KB Output is correct

Subtask #8
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 20 ms 7004 KB Output is correct
2 Correct 119 ms 18004 KB Output is correct
3 Correct 197 ms 18096 KB Output is correct
4 Correct 25 ms 7004 KB Output is correct
5 Correct 882 ms 18432 KB Output is correct
6 Correct 1770 ms 18768 KB Output is correct

Subtask #9
12.5 / 12.5

# Verdict Execution time Memory Grader output
1 Correct 20 ms 7004 KB Output is correct
2 Correct 181 ms 29372 KB Output is correct
3 Correct 200 ms 29460 KB Output is correct
4 Correct 104 ms 29268 KB Output is correct
5 Correct 20 ms 7000 KB Output is correct
6 Correct 120 ms 18004 KB Output is correct
7 Correct 220 ms 18000 KB Output is correct
8 Correct 179 ms 19124 KB Output is correct
9 Correct 190 ms 19024 KB Output is correct
10 Correct 189 ms 22192 KB Output is correct
11 Correct 168 ms 21420 KB Output is correct

Subtask #10
12.5 / 12.5

# Verdict Execution time Memory Grader output
1 Correct 20 ms 7004 KB Output is correct
2 Correct 181 ms 29372 KB Output is correct
3 Correct 200 ms 29460 KB Output is correct
4 Correct 104 ms 29268 KB Output is correct
5 Correct 20 ms 7000 KB Output is correct
6 Correct 120 ms 18004 KB Output is correct
7 Correct 220 ms 18000 KB Output is correct
8 Correct 179 ms 19124 KB Output is correct
9 Correct 190 ms 19024 KB Output is correct
10 Correct 189 ms 22192 KB Output is correct
11 Correct 168 ms 21420 KB Output is correct
12 Correct 20 ms 7052 KB Output is correct
13 Correct 461 ms 30036 KB Output is correct
14 Correct 272 ms 29776 KB Output is correct
15 Correct 684 ms 29516 KB Output is correct
16 Correct 713 ms 32340 KB Output is correct
17 Correct 22 ms 8024 KB Output is correct
18 Correct 866 ms 21332 KB Output is correct
19 Correct 1842 ms 21332 KB Output is correct
20 Correct 492 ms 22296 KB Output is correct
21 Correct 1598 ms 22436 KB Output is correct
22 Correct 982 ms 24344 KB Output is correct
23 Correct 382 ms 26240 KB Output is correct
24 Correct 229 ms 26452 KB Output is correct

Subtask #11
17.5 / 17.5

# Verdict Execution time Memory Grader output
1 Correct 20 ms 7004 KB Output is correct
2 Correct 34 ms 7304 KB Output is correct
3 Correct 41 ms 7628 KB Output is correct
4 Correct 29 ms 7468 KB Output is correct
5 Correct 24 ms 7768 KB Output is correct
6 Correct 35 ms 7516 KB Output is correct
7 Correct 22 ms 7004 KB Output is correct
8 Correct 217 ms 19244 KB Output is correct
9 Correct 209 ms 19024 KB Output is correct
10 Correct 19 ms 7256 KB Output is correct
11 Correct 191 ms 29344 KB Output is correct
12 Correct 191 ms 29264 KB Output is correct
13 Correct 102 ms 29268 KB Output is correct
14 Correct 24 ms 7116 KB Output is correct
15 Correct 121 ms 18176 KB Output is correct
16 Correct 215 ms 18088 KB Output is correct
17 Correct 216 ms 19028 KB Output is correct
18 Correct 201 ms 19032 KB Output is correct
19 Correct 191 ms 22352 KB Output is correct
20 Correct 192 ms 21328 KB Output is correct
21 Correct 205 ms 19036 KB Output is correct
22 Correct 205 ms 19024 KB Output is correct
23 Correct 207 ms 19332 KB Output is correct
24 Correct 212 ms 19456 KB Output is correct
25 Correct 281 ms 21824 KB Output is correct
26 Correct 184 ms 18348 KB Output is correct
27 Correct 178 ms 18516 KB Output is correct

Subtask #12
0 / 17.5

# Verdict Execution time Memory Grader output
1 Correct 20 ms 7004 KB Output is correct
2 Correct 34 ms 7304 KB Output is correct
3 Correct 41 ms 7628 KB Output is correct
4 Correct 29 ms 7468 KB Output is correct
5 Correct 24 ms 7768 KB Output is correct
6 Correct 35 ms 7516 KB Output is correct
7 Correct 22 ms 7004 KB Output is correct
8 Correct 217 ms 19244 KB Output is correct
9 Correct 209 ms 19024 KB Output is correct
10 Correct 19 ms 7256 KB Output is correct
11 Correct 191 ms 29344 KB Output is correct
12 Correct 191 ms 29264 KB Output is correct
13 Correct 102 ms 29268 KB Output is correct
14 Correct 24 ms 7116 KB Output is correct
15 Correct 121 ms 18176 KB Output is correct
16 Correct 215 ms 18088 KB Output is correct
17 Correct 216 ms 19028 KB Output is correct
18 Correct 201 ms 19032 KB Output is correct
19 Correct 191 ms 22352 KB Output is correct
20 Correct 192 ms 21328 KB Output is correct
21 Correct 205 ms 19036 KB Output is correct
22 Correct 205 ms 19024 KB Output is correct
23 Correct 207 ms 19332 KB Output is correct
24 Correct 212 ms 19456 KB Output is correct
25 Correct 281 ms 21824 KB Output is correct
26 Correct 184 ms 18348 KB Output is correct
27 Correct 178 ms 18516 KB Output is correct
28 Correct 22 ms 7004 KB Output is correct
29 Correct 106 ms 7340 KB Output is correct
30 Correct 75 ms 7504 KB Output is correct
31 Correct 65 ms 7504 KB Output is correct
32 Correct 51 ms 7756 KB Output is correct
33 Correct 125 ms 7540 KB Output is correct
34 Correct 25 ms 7004 KB Output is correct
35 Correct 1201 ms 19588 KB Output is correct
36 Correct 2249 ms 19716 KB Output is correct
37 Execution timed out 3551 ms 19524 KB Time limit exceeded
38 Halted 0 ms 0 KB -