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Add a lot more problems and a TODO list

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Segcolt
2025-10-18 16:54:05 -03:00
parent f82c3630cf
commit f3275cd442
72 changed files with 9550 additions and 17 deletions
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161
ITMO Academy: pilot course - Disjoint Sets Union - Step 3/A. DSU with rollback.cpp Normal file
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/* Problem URL: https://codeforces.com/edu/course/2/lesson/7/3/practice/contest/289392/problem/A */
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
template <class T, class comp = less<>>
using ordered_set = tree<T, null_type , comp , rb_tree_tag , tree_order_statistics_node_update>;
#define V vector
#define rmin(a, b) a = min(a, b)
#define rmax(a, b) a = max(a, b)
#define rep(i, lim) for (int i = 0; i < (lim); i++)
#define nrep(i, s, lim) for (int i = s; i < (lim); i++)
#define repv(i, v) for (auto &i : (v))
#define fillv(v) for (auto &itr_ : (v)) { cin >> itr_; }
#define sortv(v) sort(v.begin(), v.end())
#define all(v) (v).begin(), (v).end()
using vi = vector<int>;
using vvi = vector<vi>;
using vvvi = vector<vvi>;
using vvvvi = vector<vvvi>;
using ll = long long;
using vl = vector<ll>;
using vvl = vector<vl>;
using vvvl = vector<vvl>;
using vvvvl = vector<vvvl>;
template<class v>
auto operator<<(ostream &os, const vector<v> &vec)->ostream& {
os << vec[0];
for (size_t i = 1; i < vec.size(); i++) {
os << ' ' << vec[i];
}
os << '\n';
return os;
}
template<class v>
auto operator>>(istream &is, vector<v> &vec)->istream& {
for (auto &i : vec) {
is >> i;
}
return is;
}
template<class v>
auto operator<<(ostream &os, const vector<vector<v>> &vec)->ostream& {
for (auto &i : vec) {
os << i[0];
for (size_t j = 1; j < i.size(); j++) {
os << ' ' << i[j];
}
os << '\n';
}
return os;
}
template<class v>
auto operator>>(istream &is, vector<vector<v>> &vec)->istream& {
for (auto &i : vec) {
for (auto &j : i) {
is >> j;
}
}
return is;
}
int main()
{
ios::sync_with_stdio(false);
cin.tie(nullptr);
int n, m;
cin >> n >> m;
vi dsu(n);
vi size(n);
rep(i, n) {
dsu[i] = i;
size[i] = 1;
}
stack<pair<int, int>> re;
function<int(int)> find_p = [&](int i) {
if (dsu[i] == i) {
return i;
}
return find_p(dsu[i]);
};
int c = n;
auto join = [&](int a, int b) {
a = find_p(a);
b = find_p(b);
if (a == b) {
return;
}
if (size[a] < size[b]) {
swap(a, b);
}
re.emplace(a, b);
dsu[b] = a;
if (size[a] == size[b]) {
size[a]++;
}
c--;
};
auto rollback = [&]() {
while (re.top().first != -1) {
auto [a, b] = re.top();
re.pop();
if (size[b] == size[a] - 1) {
size[a]--;
}
dsu[b] = b;
c++;
}
re.pop();
};
while (m--) {
string op;
cin >> op;
if (op[0] == 'u') {
int a, b;
cin >> a >> b;
join(a - 1, b - 1);
cout << c << '\n';
continue;
}
if (op[0] == 'p') {
re.emplace(-1, -1);
continue;
}
rollback();
cout << c << '\n';
}
}

230
ITMO Academy: pilot course - Disjoint Sets Union - Step 3/B. Number of Connected Components on Segments.cpp Normal file
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/* Problem URL: https://codeforces.com/edu/course/2/lesson/7/3/practice/contest/289392/problem/B */
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
template <class T, class comp = less<>>
using ordered_set = tree<T, null_type , comp , rb_tree_tag , tree_order_statistics_node_update>;
#define V vector
#define rmin(a, b) a = min(a, b)
#define rmax(a, b) a = max(a, b)
#define rep(i, lim) for (int i = 0; i < (lim); i++)
#define nrep(i, s, lim) for (int i = s; i < (lim); i++)
#define repv(i, v) for (auto &i : (v))
#define fillv(v) for (auto &itr_ : (v)) { cin >> itr_; }
#define sortv(v) sort(v.begin(), v.end())
#define all(v) (v).begin(), (v).end()
using vi = vector<int>;
using vvi = vector<vi>;
using vvvi = vector<vvi>;
using vvvvi = vector<vvvi>;
using ll = long long;
using vl = vector<ll>;
using vvl = vector<vl>;
using vvvl = vector<vvl>;
using vvvvl = vector<vvvl>;
template<class v>
auto operator<<(ostream &os, const vector<v> &vec)->ostream& {
os << vec[0];
for (size_t i = 1; i < vec.size(); i++) {
os << ' ' << vec[i];
}
os << '\n';
return os;
}
template<class v>
auto operator>>(istream &is, vector<v> &vec)->istream& {
for (auto &i : vec) {
is >> i;
}
return is;
}
template<class v>
auto operator<<(ostream &os, const vector<vector<v>> &vec)->ostream& {
for (auto &i : vec) {
os << i[0];
for (size_t j = 1; j < i.size(); j++) {
os << ' ' << i[j];
}
os << '\n';
}
return os;
}
template<class v>
auto operator>>(istream &is, vector<vector<v>> &vec)->istream& {
for (auto &i : vec) {
for (auto &j : i) {
is >> j;
}
}
return is;
}
int main()
{
ios::sync_with_stdio(false);
cin.tie(nullptr);
int n, m;
cin >> n >> m;
vi dsu(n);
vi size(n);
rep(i, n) {
dsu[i] = i;
size[i] = 1;
}
stack<pair<int, int>> ops;
int c = n;
function<int(int)> find_p = [&](int i) {
if (dsu[i] == i) {
return i;
}
return find_p(dsu[i]);
};
auto join = [&](int a, int b) {
a = find_p(a);
b = find_p(b);
if (a == b) {
return;
}
if (size[a] < size[b]) {
swap(a, b);
}
dsu[b] = a;
if (size[a] == size[b]) {
size[a]++;
}
ops.emplace(a, b);
c--;
};
auto save = [&]() {
ops.emplace(-1, -1);
};
auto rollback = [&]() {
while (ops.top().first != -1) {
auto [a, b] = ops.top();
ops.pop();
if (size[b] == size[a] - 1) {
size[a]--;
}
dsu[b] = b;
c++;
}
ops.pop();
};
V<pair<int, int>> edges(m);
repv(i, edges) {
cin >> i.first >> i.second;
i.first--, i.second--;
}
int q;
cin >> q;
static int len = sqrt(m) + 1;
struct query {
int l;
int r;
int i;
bool operator<(query &b) {
if (l / len != b.l / len) {
return l / len < b.l / len;
}
return r < b.r;
}
};
V<query> queries(q);
rep(i, q) {
cin >> queries[i].l >> queries[i].r;
queries[i].l--, queries[i].r--;
queries[i].i = i;
}
sortv(queries);
vi ans(q);
int now = 0;
int calc = 1;
repv(i, queries) {
int cur = i.l / len;
if (cur > now) {
now = cur;
calc = cur + 1;
while (!ops.empty()) {
ops.pop();
}
rep(i, n) {
dsu[i] = i;
size[i] = 1;
}
c = n;
}
int stop = i.r / len;
if (cur == stop) {
save();
nrep(j, i.l, i.r + 1) {
join(edges[j].first, edges[j].second);
}
ans[i.i] = c;
rollback();
continue;
}
while (calc < stop) {
nrep(i, calc * len, (calc + 1) * len) {
join(edges[i].first, edges[i].second);
}
calc++;
}
save();
nrep(j, calc * len, i.r + 1) {
join(edges[j].first, edges[j].second);
}
nrep(j, i.l, min((now + 1) * len, m)) {
join(edges[j].first, edges[j].second);
}
ans[i.i] = c;
rollback();
}
repv(i, ans) {
cout << i << '\n';
}
}

242
ITMO Academy: pilot course - Disjoint Sets Union - Step 3/C. Dynamic Connectivity Offline.cpp Normal file
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/* Problem URL: https://codeforces.com/edu/course/2/lesson/7/3/practice/contest/289392/problem/C */
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
template <class T, class comp = less<>>
using ordered_set = tree<T, null_type , comp , rb_tree_tag , tree_order_statistics_node_update>;
#define V vector
#define rmin(a, b) a = min(a, b)
#define rmax(a, b) a = max(a, b)
#define rep(i, lim) for (int i = 0; i < (lim); i++)
#define nrep(i, s, lim) for (int i = s; i < (lim); i++)
#define repv(i, v) for (auto &i : (v))
#define fillv(v) for (auto &itr_ : (v)) { cin >> itr_; }
#define sortv(v) sort(v.begin(), v.end())
#define all(v) (v).begin(), (v).end()
using vi = vector<int>;
using vvi = vector<vi>;
using vvvi = vector<vvi>;
using vvvvi = vector<vvvi>;
using ll = long long;
using vl = vector<ll>;
using vvl = vector<vl>;
using vvvl = vector<vvl>;
using vvvvl = vector<vvvl>;
template<class v>
auto operator<<(ostream &os, const vector<v> &vec)->ostream& {
os << vec[0];
for (size_t i = 1; i < vec.size(); i++) {
os << ' ' << vec[i];
}
os << '\n';
return os;
}
template<class v>
auto operator>>(istream &is, vector<v> &vec)->istream& {
for (auto &i : vec) {
is >> i;
}
return is;
}
template<class v>
auto operator<<(ostream &os, const vector<vector<v>> &vec)->ostream& {
for (auto &i : vec) {
os << i[0];
for (size_t j = 1; j < i.size(); j++) {
os << ' ' << i[j];
}
os << '\n';
}
return os;
}
template<class v>
auto operator>>(istream &is, vector<vector<v>> &vec)->istream& {
for (auto &i : vec) {
for (auto &j : i) {
is >> j;
}
}
return is;
}
int main()
{
ios::sync_with_stdio(false);
cin.tie(nullptr);
int n, m;
cin >> n >> m;
struct query {
int type;
int l;
int r;
int u;
int v;
int i;
};
V<query> queries;
vi ans;
map<pair<int, int>, int> prev;
int time = 0;
rep(i, m) {
char op;
cin >> op;
if (op == '?') {
queries.emplace_back(1, time, time, 0, 0, ans.size());
ans.emplace_back();
continue;
}
int a, b;
cin >> a >> b;
a--, b--;
if (a > b) {
swap(a, b);
}
if (op == '-') {
queries[prev[{a, b}]].r = time;
time++;
continue;
}
time++;
prev[{a, b}] = queries.size();
queries.emplace_back(0, time, INT32_MAX >> 1, a, b, -1);
}
vi dsu(n);
vi size(n);
stack<pair<int, int>> rev;
int c;
auto init = [&]() {
c = n;
rep(i, n) {
dsu[i] = i;
size[i] = 1;
}
};
init();
function<int(int)> find_p = [&](int i) {
if (dsu[i] == i) {
return i;
}
return find_p(dsu[i]);
};
auto join = [&](int a, int b) {
a = find_p(a);
b = find_p(b);
if (a == b) {
return;
}
c--;
if (size[a] < size[b]) {
swap(a, b);
}
if (size[a] == size[b]) {
size[a]++;
}
dsu[b] = a;
rev.emplace(a, b);
};
auto save = [&]() {
rev.emplace(-1, -1);
};
auto rollback = [&]() {
while (rev.top().first != -1) {
auto [a, b] = rev.top();
rev.pop();
if (size[b] == size[a] - 1) {
size[a]--;
}
dsu[b] = b;
c++;
}
rev.pop();
};
function<void(int, int, V<query>&)> func = [&](int l, int r, V<query> &queries) {
if (l == r) {
save();
repv(i, queries) {
if (i.type == 0 && l >= i.l && r <= i.r) {
join(i.u, i.v);
}
}
repv(i, queries) {
if (i.type == 1 && i.l == l) {
ans[i.i] = c;
}
}
rollback();
return;
}
V<query> queries2;
save();
repv(i, queries) {
if (l >= i.l && r <= i.r) {
join(i.u, i.v);
continue;
}
if (l <= i.r && i.l <= r) {
queries2.emplace_back(i);
}
}
int mid = (l + r) >> 1;
func(l, mid, queries2);
func(mid + 1, r, queries2);
rollback();
};
func(0, time, queries);
repv(i, ans) {
cout << i << '\n';
}
}