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Codeforces-solutions/Codeforces Round 890 (Div. 2) supported by Constructor Institute/C. To Become Max.cpp
2026-03-16 17:09:23 -03:00

160 lines
3.2 KiB
C++

/* Problem URL: https://codeforces.com/problemset/problem/1856/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;
}
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;
ll ans = *max_element(all(a));
rep(i, n - 1) {
ll co = 0;
nrep(j, i + 1, n) {
if (a[j] < a[i] - (j - i - 1)) {
co += a[i] - (j - i - 1) - a[j];
if (co >= k) {
break;
}
continue;
}
if (co == k) {
break;
}
ll lk = k - co;
ll low = 0;
ll high = a[j] - a[i] + j - i - 1;
ll act = 0;
while (low <= high) {
ll mid = (low + high) >> 1;
ll cost = mid * (j - i);
if (cost < lk) {
low = mid + 1;
act = mid;
continue;
}
high = mid - 1;
}
rmax(ans, a[i] + act + 1);
a[i] += act;
co += act * (j - i);
if (a[j] < a[i] - (j - i - 1)) {
co += a[i] - (j - i - 1) - a[j];
if (co >= k) {
break;
}
}
}
}
cout << ans << '\n';
}
int main()
{
ios::sync_with_stdio(false);
cin.tie(nullptr);
pre();
int t;
(TEST && cin >> t) || (t = 1);
while (t--) {
solve();
}
}