#include<bits/stdc++.h>
using namespace std ;
typedef long long ll ;
typedef pair <int ,int> pii ;
const int MAXN = 2e5 + 5;
const int MOD = 1e9 + 7 ;
#define F first
#define S second
#define debug(x) cerr << #x << " :" << x << "\n"
int q ,n ,st[MAXN] ,ed[MAXN] ,child[MAXN * 31][2] ,newint ,a[MAXN] ,b[MAXN] ,dist[MAXN] ,tme ,idx[MAXN] ,len ,root ,x;
vector <pii> G[MAXN] ;
set <int> s[MAXN * 31] ;
string sq[MAXN] ;
void dfs(int &u){
st[u] = tme++ ;
for (auto [v ,w] : G[u]){
dist[v] = dist[u] ^ w ;
dfs(v) ;
}
ed[u] = tme++ ;
}
void add(int &p ,int &id){
root = 0 ;
for (int i = 30; i >= 0; i--){
x = (p >> i) & 1 ;
if (child[root][x] == -1){
child[root][x] = ++newint ;
}
root = child[root][x] ;
s[root].insert(st[id]) ;
}
}
bool check(int &id ,int &v){
if (s[id].lower_bound(st[v]) == s[id].end()){
return false ;
}
return (*s[id].lower_bound(st[v])) <= ed[v] ;
}
void ans(int &u ,int &v){
len = dist[u] ;
root = 0 ;
for (int i = 30; i >= 0; i--){
x = (len >> i) & 1 ;
if (child[root][1 - x] != -1 && check(child[root][1 - x] ,v)){
root = child[root][1 - x] ;
if (!x){
len += (1 << i) ;
}
}
else {
if (x == 1){
len -= (1 << i) ;
}
root = child[root][x] ;
}
}
cout << len << "\n" ;
}
int main (){
ios::sync_with_stdio(false); cin.tie(0) ;cout.tie(0) ;
memset(child ,-1 ,sizeof child) ;
cin >> q ;
n = 1 ;
for (int i = 1; i <= q; i++){
cin >> sq[i] >> a[i] >> b[i] ;
if (sq[i][0] == 'A'){
n++ ;
G[a[i]].push_back({n ,b[i]}) ;
idx[i] = n ;
}
}
dfs(1) ;
add(dist[1] ,1) ;
for (int i = 1; i <= q; i++){
if (sq[i][0] == 'Q'){
ans(a[i] ,b[i]) ;
}
else {
add(dist[idx[i]] ,idx[i]) ;
}
}
return 0 ;
}
Compilation message
klasika.cpp: In function 'int main()':
klasika.cpp:79:6: error: cannot bind non-const lvalue reference of type 'int&' to an rvalue of type 'int'
79 | dfs(1) ;
| ^
klasika.cpp:17:15: note: initializing argument 1 of 'void dfs(int&)'
17 | void dfs(int &u){
| ~~~~~^
klasika.cpp:80:15: error: cannot bind non-const lvalue reference of type 'int&' to an rvalue of type 'int'
80 | add(dist[1] ,1) ;
| ^
klasika.cpp:26:23: note: initializing argument 2 of 'void add(int&, int&)'
26 | void add(int &p ,int &id){
| ~~~~~^~
