#include <iostream>
#include <vector>
#include <map>
#include <algorithm>
using std::cout;
using std::endl;
using std::vector;
using ll = long long;
struct Hash {
const ll MOD1 = 1e9 + 7;
const ll MOD2 = 1e9 + 9;
ll h1, h2;
Hash(ll h1, ll h2) : h1(h1), h2(h2) { }
Hash() : h1(0), h2(0) { }
inline Hash operator+(const Hash& o) {
return Hash((h1 + o.h1) % MOD1, (h2 + o.h2) % MOD2);
}
inline Hash operator-(const Hash& o) {
return Hash((h1 - o.h1 + MOD1) % MOD1, (h2 - o.h2 + MOD2) % MOD2);
}
Hash& operator=(const Hash& h) {
h1 = h.h1;
h2 = h.h2;
return *this;
}
inline Hash exp(const ll& n) {
return Hash(h1 * n % MOD1, h2 * n % MOD2);
}
inline ll hash() const {
return 1LL * h1 * MOD2 + h2;
}
inline vector<Hash> zero_pairs() {
return {
Hash(MOD1 - h1, MOD2 - h2), Hash(-h1, -h2),
Hash(-h1, MOD2 - h2), Hash(MOD1 - h1, -h2),
};
}
};
bool operator<(const Hash& h1, const Hash& h2) {
return h1.h1 != h2.h1 ? h1.h1 < h2.h1 : h1.h2 < h2.h2;
}
bool operator==(const Hash& h1, const Hash& h2) {
return h1.h1 == h2.h1 && h1.h2 == h2.h2;
}
bool operator!=(const Hash& h1, const Hash& h2) {
return !(h1 == h2);
}
struct HashFn {
std::size_t operator() (const Hash& h) const {
return h.hash();
}
};
class DominikArray {
private:
const ll POW = 1e6 + 3;
vector<int> arr;
vector<int> sorted;
vector<int> parent;
vector<int> size;
int bad_num = 0; // # of bad components (used for type 3)
std::unordered_map<int, Hash> elem_pow; // raise to the power of the value
// the current hash of a component
vector<Hash> hash;
// the needed hash for a component to be able to be sorted
vector<Hash> req_hash;
// the hash differences of the bad components
std::unordered_map<Hash, ll, HashFn> bad_diff;
ll cloud_pairs = 0; // # of valid component pairs (used for type 4)
int get_top(int n) {
return parent[n] == n ? n : (parent[n] = get_top(parent[n]));
}
/** checks if a component is unsortable (n is a top node) */
inline bool is_unsortable(int n) {
return hash[n] != req_hash[n];
}
/** add a bad component to the log & update data accordingly */
void add_if_bad(int n) {
if (is_unsortable(n)) {
// one more bad component
bad_num++;
Hash diff = req_hash[n] - hash[n];
bad_diff[diff] += size[n];
for (const Hash& zp : diff.zero_pairs()) {
cloud_pairs += bad_diff[zp] * size[n];
}
}
}
void remove_if_bad(int n) {
if (is_unsortable(n)) {
bad_num--;
Hash diff = req_hash[n] - hash[n];
bad_diff[diff] -= size[n];
for (const Hash& zp : diff.zero_pairs()) {
cloud_pairs -= bad_diff[zp] * size[n];
}
}
}
public:
DominikArray(vector<int> arr)
: arr(arr), parent(arr.size()), size(arr.size(), 1),
hash(arr.size()), req_hash(arr.size()) {
sorted = arr;
std::sort(sorted.begin(), sorted.end());
// perform coordinate compression
Hash curr_hsh(1, 1);
for (int i : sorted) {
if (!elem_pow.count(i)) {
elem_pow[i] = curr_hsh;
curr_hsh = curr_hsh.exp(POW);
}
}
// set up DSU and the hashes
for (int i = 0; i < arr.size(); i++) {
parent[i] = i;
hash[i] = elem_pow[arr[i]];
req_hash[i] = elem_pow[sorted[i]];
add_if_bad(i);
}
}
void swap(int a, int b) {
int top_a = get_top(a);
int top_b = get_top(b);
// temporarily take them out of the bad log (if applicable)
remove_if_bad(top_a);
remove_if_bad(top_b);
// change the hashes of the two components
hash[top_a] = hash[top_a] + elem_pow[arr[b]] - elem_pow[arr[a]];
hash[top_b] = hash[top_b] + elem_pow[arr[a]] - elem_pow[arr[b]];
// add the back (if applicable)
add_if_bad(top_a);
add_if_bad(top_b);
std::swap(arr[a], arr[b]);
}
void link(int a, int b) {
a = get_top(a);
b = get_top(b);
if (a == b) {
return;
}
if (size[a] < size[b]) {
return link(b, a);
}
remove_if_bad(a);
remove_if_bad(b);
// standard dsu operations
size[a] += size[b];
parent[b] = a;
// add the hash of the smaller component to the bigger one
hash[a] = hash[a] + hash[b];
req_hash[a] = req_hash[a] + req_hash[b];
// since b's merged into a, we just add a back (if applicable)
add_if_bad(a);
}
bool sortable() {
// for everything to be sortable, there can't be any bad components
return bad_num == 0;
}
ll needed_pair_num() {
return cloud_pairs;
}
};
// https://oj.uz/problem/view/COCI16_zamjene (input omitted due to length)
int main() {
std::ios::sync_with_stdio(false);
std::cin.tie(NULL);
int arr_len;
int query_num;
std::cin >> arr_len >> query_num;
vector<int> arr(arr_len);
for (int& i : arr) {
std::cin >> i;
}
DominikArray array(arr);
for (int q = 0; q < query_num; q++) {
int type;
std::cin >> type;
int a, b; // not necessarily used (queries of type 3 & 4)
switch (type) {
case 1:
std::cin >> a >> b;
array.swap(--a, --b);
break;
case 2:
std::cin >> a >> b;
array.link(--a, --b);
break;
case 3:
cout << (array.sortable() ? "DA" : "NE") << '\n';
break;
case 4:
cout << array.needed_pair_num() << '\n';
break;
};
}
}
Compilation message
palinilap.cpp: In constructor 'DominikArray::DominikArray(std::vector<int>)':
palinilap.cpp:136:31: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
136 | for (int i = 0; i < arr.size(); i++) {
| ~~^~~~~~~~~~~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
1 ms |
212 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
0 ms |
212 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
0 ms |
340 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
