A bunch new problems

This commit is contained in:
2026-03-16 17:09:23 -03:00
parent 41d9ca1dc8
commit 2d314df46f
65 changed files with 9058 additions and 78 deletions

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/* Problem URL: https://codeforces.com/problemset/problem/1986/E */
#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;
}
const int oo = INT32_MAX >> 1;
const ll OO = INT64_MAX >> 1;
void pre()
{
}
#define TEST 1
void solve()
{
int n;
ll k;
cin >> n >> k;
vl a(n);
cin >> a;
map<ll, vl> c;
rep(i, n) {
c[a[i] % k].push_back(a[i]);
}
int oc = 0;
repv(i, c) {
oc += i.second.size() & 1;
}
if (oc > 1) {
cout << "-1\n";
return;
}
auto func = [&](vl &v) -> int {
if (v.size() <= 1) {
return 0;
}
int n = v.size();
vl suf(n + 1);
suf[n - 2] = (v.end()[-1] - v.end()[-2]) / k;
for (int i = n - 4; i >= 0; i -= 2) {
suf[i] = suf[i + 2] + (v[i + 1] - v[i]) / k;
}
ll ans = OO;
ll sum = 0;
rep(i, n) {
if (i & 1) {
rmin(ans, (v[i + 1] - v[i - 1]) / k + suf[i + 2] + sum);
sum += (v[i] - v[i - 1]) / k;
continue;
}
rmin(ans, sum + suf[i + 1]);
}
return ans;
};
ll ans = 0;
repv(i, c) {
auto &v = i.second;
sortv(v);
if (v.size() & 1) {
ans += func(v);
continue;
}
nrep(j, 1, v.size()) {
ans += (v[j] - v[j - 1]) / k;
j++;
}
}
cout << ans << '\n';
}
int main()
{
ios::sync_with_stdio(false);
cin.tie(nullptr);
pre();
int t;
(TEST && cin >> t) || (t = 1);
while (t--) {
solve();
}
}

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/* Problem URL: https://codeforces.com/problemset/problem/1986/F */
#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;
}
const int oo = INT32_MAX >> 1;
const ll OO = INT64_MAX >> 1;
void pre()
{
}
#define TEST 1
void solve()
{
int n, m;
cin >> n >> m;
V<V<pair<int, int>>> graph(n);
V<bool> rem(m);
while (m--) {
int a, b;
cin >> a >> b;
a--, b--;
graph[a].emplace_back(b, m);
graph[b].emplace_back(a, m);
}
V<bool> vis(n);
vi t(n);
vi mi(n);
int tim = 0;
int tt = 1;
function<int(int, int)> dfs = [&](int i, int p) {
vis[i] = true;
t[i] = tim++;
mi[i] = t[i];
for (auto [j, ind] : graph[i]) {
if (j == p) {
continue;
}
if (vis[j]) {
rmin(mi[i], t[j]);
continue;
}
rmin(mi[i], dfs(j, i));
if (mi[j] > t[i]) {
rem[ind] = true;
tt++;
}
}
return mi[i];
};
dfs(0, 0);
vl c(tt);
vi g(n);
vvi act(tt);
int cur = 0;
fill(all(vis), false);
function<void(int)> func = [&](int i) {
vis[i] = true;
g[i] = cur;
c[cur]++;
for (auto [j, ind] : graph[i]) {
if (vis[j] || rem[ind]) {
continue;
}
func(j);
}
};
rep(i, n) {
if (vis[i]) {
continue;
}
func(i);
cur++;
}
rep(i, n) {
for (auto [j, ind] : graph[i]) {
if (rem[ind]) {
act[g[i]].push_back(g[j]);
act[g[j]].push_back(g[i]);
}
}
}
repv(i, act) {
sortv(i);
i.erase(unique(all(i)), i.end());
}
ll ans = (ll)n * (n - 1) / 2;
function<ll(int, int)> calc = [&](int i, int p) {
ll count = c[i];
repv(j, act[i]) {
if (j == p) {
continue;
}
ll tm = calc(j, i);
rmin(ans, tm * (tm - 1) / 2 + (n - tm) * (n - tm - 1) / 2);
count += tm;
}
return count;
};
calc(0, 0);
cout << ans << '\n';
}
int main()
{
ios::sync_with_stdio(false);
cin.tie(nullptr);
pre();
int t;
(TEST && cin >> t) || (t = 1);
while (t--) {
solve();
}
}