156 lines
3.3 KiB
C++
156 lines
3.3 KiB
C++
/* Problem URL: https://codeforces.com/contest/893/problem/D */
|
|
|
|
#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;
|
|
ll d;
|
|
cin >> n >> d;
|
|
|
|
vl fds(n);
|
|
cin >> fds;
|
|
|
|
ll test = 0;
|
|
vl trans(n);
|
|
rep(i, n) {
|
|
test += fds[i];
|
|
|
|
if (test > d) {
|
|
cout << "-1\n";
|
|
return 0;
|
|
}
|
|
|
|
trans[i] = test;
|
|
}
|
|
|
|
vvl sparse(n, vl(20));
|
|
// vvl minimal(n, vl(20));
|
|
|
|
rep(i, n) {
|
|
sparse[i][0] = trans[i];
|
|
// minimal[i][0] = trans[i];
|
|
}
|
|
|
|
nrep(j, 1, 20) {
|
|
for (int i = 0; i + (1 << (j - 1)) < n; i++) {
|
|
sparse[i][j] = max(sparse[i][j - 1], sparse[i + (1 << (j - 1))][j - 1]);
|
|
// minimal[i][j] = min(minimal[i][j - 1], minimal[i + (j << 1)][j - 1]);
|
|
}
|
|
}
|
|
|
|
auto query = [&](int l, int r) {
|
|
int log = 31 - __builtin_clz(r - l + 1);
|
|
|
|
return max(sparse[l][log], sparse[r - (1 << log) + 1][log]);
|
|
};
|
|
|
|
// auto minquery = [&](int l, int r) {
|
|
// int log = 31 - __builtin_clz(r - l + 1);
|
|
//
|
|
// return min(minimal[l][log], minimal[r - (1 << log) + 1][log]);
|
|
// };
|
|
|
|
int i = 0;
|
|
|
|
ll added = 0;
|
|
int ans = 0;
|
|
|
|
rep(i, n) {
|
|
if (fds[i] == 0) {
|
|
if (trans[i] + added < 0) {
|
|
ll maximal = query(i, n - 1);
|
|
ll act = trans[i] + added;
|
|
|
|
ll now = d - (maximal + added);
|
|
|
|
if (now < -act) {
|
|
cout << "-1\n";
|
|
return 0;
|
|
}
|
|
|
|
ans++;
|
|
added += now;
|
|
}
|
|
}
|
|
}
|
|
|
|
cout << ans << '\n';
|
|
}
|