2025-09-12 14:50:25 -03:00

132 lines
2.5 KiB
C++

/* Problem URL: https://codeforces.com/group/SmO1tpanN1/contest/523096/problem/F */
#include <bits/stdc++.h>
using namespace std;
#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;
vl pref(n + 1);
rep(i, n) {
pref[i + 1] = pref[i] + fds[i];
}
int i = 0;
int j = 0;
int ans = 0;
while (i < n) {
while (pref[i + 1] - pref[j] > d) {
j++;
}
if (pref[i + 1] - pref[j] == d) {
ans++;
}
i++;
}
if (pref.back() == d) {
cout << ans + (n - 1) << '\n';
return 0;
}
rep(i, n) {
int low = i + 2;
int high = n;
while (low <= high) {
int mid = (low + high) / 2;
if (pref.back() - (pref[mid - 1] - pref[i + 1]) == d) {
ans++;
break;
}
if (pref.back() - (pref[mid - 1] - pref[i + 1]) > d) {
low = mid + 1;
continue;
}
high = mid - 1;
}
}
cout << ans << '\n';
}