CSES - Aalto Competitive Programming 2024 - wk7 Homework - Results
Submission details
Task:Company Queries II
Sender:ilyas.ben
Submission time:2024-10-24 19:36:35 +0300
Language:C++ (C++20)
Status:COMPILE ERROR

Compiler report

input/code.cpp: In function 'int main()':
input/code.cpp:77:14: error: expected '}' at end of input
   77 |     return 0;
      |              ^
input/code.cpp:54:12: note: to match this '{'
   54 | int main() {
      |            ^

Code

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
const int MAXN = 200001;
const int LOG = 18;
vector<int> adj[MAXN];
int up[MAXN][LOG];
int depth[MAXN];
void dfs(int v, int parent) {
up[v][0] = parent;
for (int i = 1; i < LOG; i++) {
if (up[v][i - 1] != -1) {
up[v][i] = up[up[v][i - 1]][i - 1];
} else {
up[v][i] = -1;
}
}
for (int u : adj[v]) {
if (u != parent) {
depth[u] = depth[v] + 1;
dfs(u, v);
}
}
}
int lca(int a, int b) {
if (depth[a] < depth[b]) swap(a, b);
for (int i = LOG - 1; i >= 0; i--) {
if (depth[a] - (1 << i) >= depth[b]) {
a = up[a][i];
}
}
if (a == b) return a;
for (int i = LOG - 1; i >= 0; i--) {
if (up[a][i] != up[b][i]) {
a = up[a][i];
b = up[b][i];
}
}
return up[a][0];
}
int main() {
ios::sync_with_stdio(false);
cin.tie(0);
int n, q;
cin >> n >> q;
for (int i = 2; i <= n; i++) {
int boss;
cin >> boss;
adj[boss].push_back(i);
adj[i].push_back(boss);
}
depth[1] = 0;
dfs(1, -1);
while (q--) {
int a, b;
cin >> a >> b;
cout << lca(a, b) << "\n";
}
return 0;