#include <bits/stdc++.h>
#define lsb(x) (x & (-x))
#define ll long long
#define ull unsigned long long
#define ld long double
// 217
// 44
using namespace std;
const int MAXN = (int) 1e5;
int nxt[MAXN + 1];
struct Fenwick {
vector <int> arr;
int n;
inline void init(int _n) {
n = _n;
arr.resize(n + 1);
}
inline void update(int pos, int val) {
for(int i = pos; i <= n; i += lsb(i)) {
arr[i] += val;
}
}
inline int query(int pos) {
int ans = 0;
for(int i = pos; i > 0; i -= lsb(i)) {
ans += arr[i];
}
return ans;
}
inline int sum(int l, int r) {
return query(r) - query(l - 1);
}
}aib_cyc;
Fenwick aib[MAXN + 1];
bool vis[MAXN + 1];
inline void get_cycle(vector <int> &cycle) {
int nod = 1;
vector <int> nodes;
while(vis[nod] == 0) {
nodes.push_back(nod);
vis[nod] = 1;
nod = nxt[nod];
}
reverse(nodes.begin(), nodes.end());
while(nodes.back() != nod) {
nodes.pop_back();
}
swap(nodes, cycle);
cycle.push_back(0);
reverse(cycle.begin(), cycle.end());
memset(vis, 0, sizeof(vis));
}
bool in_cyc[MAXN + 1];
int pos[MAXN + 1], id[MAXN + 1];
vector <int> g[MAXN + 1];
int first[MAXN + 1], last[MAXN + 1];
int sz[MAXN + 1], lvl[MAXN + 1];
void dfs(int nod, int x) {
first[nod] = ++sz[x];
id[nod] = x;
for(auto it : g[nod]) {
lvl[it] = lvl[nod] + 1;
dfs(it, x);
}
last[nod] = ++sz[x];
}
inline int solve_cyc_cyc(int a, int b) {
if(pos[a] <= pos[b]) {
if(aib_cyc.sum(pos[a], pos[b] - 1) == 0) {
return pos[b] - pos[a];
}
return -1;
}
if(aib_cyc.sum(pos[a], aib_cyc.n) + aib_cyc.sum(1, pos[b]) == 0) {
return aib_cyc.n - pos[a] + pos[b];
}
return -1;
}
inline int solve_tree_tree(int a, int b, bool t) {
if(id[a] != id[b]) {
return -1;
}
if(first[b] <= first[a] && last[a] <= last[b] && aib[id[a]].sum(first[b] + t, first[a]) == 0) {
return lvl[a] - lvl[b];
}
return -1;
}
inline int solve_tree_cyc(int a, int b) {
if(solve_cyc_cyc(nxt[id[a]], b) == -1 || solve_tree_tree(a, id[a], 0) == -1) {
return -1;
}
return solve_cyc_cyc(nxt[id[a]], b) + solve_tree_tree(a, id[a], 0) + 1;
}
int main() {
//ifstream cin("A.in");
//ofstream cout("A.out");
int i, n, m;
ios::sync_with_stdio(false);
cin.tie(0), cout.tie(0);
cin >> n;
for(i = 1; i <= n; i++) {
cin >> nxt[i];
}
vector <int> cycle;
get_cycle(cycle);
int cyc_sz = (int) cycle.size() - 1;
for(i = 1; i <= cyc_sz; i++) {
id[cycle[i]] = cycle[i];
pos[cycle[i]] = i;
vis[cycle[i]] = 1;
in_cyc[cycle[i]] = 1;
}
for(i = 1; i <= n; i++) {
if(vis[nxt[i]] == 0 && vis[i] == 0) {
g[nxt[i]].push_back(i);
}
}
for(i = 1; i <= n; i++) {
if(vis[nxt[i]] == 1 && vis[i] == 0) {
dfs(i, i);
}
}
aib_cyc.init(cyc_sz);
for(i = 1; i <= n; i++) {
aib[i].init(sz[i]);
}
cin >> m;
while(m > 0) {
m--;
int type, a, b;
cin >> type >> a;
if(type == 1) {
if(in_cyc[a]) {
aib_cyc.update(pos[a], 1);
}
else {
aib[id[a]].update(first[a], 1);
aib[id[a]].update(last[a], -1);
}
}
else {
cin >> b;
int ans = -1;
if(in_cyc[a] && in_cyc[b]) {
ans = solve_cyc_cyc(a, b);
}
else if(!in_cyc[a] && !in_cyc[b]) {
ans = solve_tree_tree(a, b, 1);
}
else if(in_cyc[b]) {
if(a == 1 && b == 6)
cerr << a << " " << id[a] << "\n";
ans = solve_tree_cyc(a, b);
}
cout << ans << "\n";
}
}
//cin.close();
//cout.close();
return 0;
}
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Runtime error |
14 ms |
11996 KB |
Execution killed with signal 11 (could be triggered by violating memory limits) |
| 2 |
Halted |
0 ms |
0 KB |
- |
