Submission #441933

#	Time	Username	Problem	Language	Result	Execution time	Memory
441933		parsabahrami	Birthday gift (IZhO18_treearray)	C++17	56 / 100	598 ms	262148 KiB

treearray

/* I do it for the glory */
#include <bits/stdc++.h>
 
using namespace std;

typedef long long int ll;
typedef pair<int, int> pii;
 
#define SZ(x)                       (int) x.size()
#define F                           first
#define S                           second

const int N = 2e5 + 10, MOD = 1e9 + 7, SQ = 500;
int H[N], P[19][N], A[N], B[N], M[N / SQ + 1][N], M2[N / SQ + 1][N], n, m, q;
vector<int> adj[N];

void preDFS(int v, int p = -1) {
    if (!~p) P[0][v] = v;
    for (int i = 1; i < 19; i++)
        P[i][v] = P[i - 1][P[i - 1][v]];
    for (int &u : adj[v]) 
        if (u != p) 
            H[u] = H[v] + 1, P[0][u] = v, preDFS(u, v);
}

int LCA(int u, int v) {
    if (H[u] < H[v]) swap(u, v);
    for (int i = H[u] - H[v]; i; i -= i & -i) 
        u = P[__builtin_ctz(i)][u];
    for (int i = 18; ~i; i--) 
        if (P[i][u] != P[i][v]) 
            u = P[i][u], v = P[i][v];
    return u == v ? v : P[0][v];
}

void upd(int id, int v) {
    M2[id / SQ][A[id]]--;
    A[id] = v;
    M2[id / SQ][A[id]]++;
    if (id) {
        M[(id - 1) / SQ][B[id - 1]]--;
        B[id - 1] = LCA(A[id], A[id - 1]);
        M[(id - 1) / SQ][B[id - 1]]++; 
    }
    if (id + 1 < m) { 
        M[id / SQ][B[id]]--;
        B[id] = LCA(A[id], A[id + 1]);
        M[id / SQ][B[id]]++;
    }
}

int main() {
    scanf("%d%d%d", &n, &m, &q);
    for (int i = 1; i < n; i++) {
        int u, v; scanf("%d%d", &u, &v);
        adj[u].push_back(v), adj[v].push_back(u);
    }
    preDFS(1);
    for (int i = 0; i < m; i++) {
        scanf("%d", &A[i]); M2[i / SQ][A[i]]++;
        if (i) B[i - 1] = LCA(A[i - 1], A[i]), M[(i - 1) / SQ][B[i - 1]]++;
    }
    for (; q; q--) {
        int t; scanf("%d", &t);
        if (t < 2) {
            int p, v; scanf("%d%d", &p, &v);
            upd(p - 1, v);
        } else {
            int l, r, v; scanf("%d%d%d", &l, &r, &v);
            pii ret = {-1, -1}; int f = 0; l--, r--; r--;
            for (int i = l; i <= r && !f; ) {
                if (i % SQ == 0 && i + SQ - 1 <= r) {
                    if (M[i / SQ][v]) {
                        for (int j = i; j < i + SQ && !f; j++) 
                            if (B[j] == v) { f = 1, ret = {j + 1, j + 2}; }
                    } else i += SQ;
                } else {
                    if (B[i] == v) { f = 1, ret = {i + 1, i + 2}; }
                    else i++;
                }
            }
            for (int i = l; i <= r + 1 && !f; ) {
                if (i % SQ == 0 && i + SQ <= r) {
                    if (M2[i / SQ][v]) {
                        for (int j = i; j < i + SQ && !f; j++) {
                            if (A[j] == v) { f = 1; ret = {j + 1, j + 1}; }
                        }
                    } else i += SQ;
                } else {
                    if (A[i] == v) { f = 1; ret = {i + 1, i + 1}; }
                    else i++;
                }
            }
            printf("%d %d\n", ret.F, ret.S);
        }
    }
    return 0;
}

Compilation message (stderr)

treearray.cpp: In function 'int main()':
treearray.cpp:53:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   53 |     scanf("%d%d%d", &n, &m, &q);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~~~~
treearray.cpp:55:24: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   55 |         int u, v; scanf("%d%d", &u, &v);
      |                   ~~~~~^~~~~~~~~~~~~~~~
treearray.cpp:60:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   60 |         scanf("%d", &A[i]); M2[i / SQ][A[i]]++;
      |         ~~~~~^~~~~~~~~~~~~
treearray.cpp:64:21: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   64 |         int t; scanf("%d", &t);
      |                ~~~~~^~~~~~~~~~
treearray.cpp:66:28: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   66 |             int p, v; scanf("%d%d", &p, &v);
      |                       ~~~~~^~~~~~~~~~~~~~~~
treearray.cpp:69:31: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   69 |             int l, r, v; scanf("%d%d%d", &l, &r, &v);
      |                          ~~~~~^~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 12 / 12
• Subtask 2: 18 / 18
• Subtask 3: 26 / 26
• Subtask 4: 0 / 44