// Om Namah Shivaya
// GM in 113 days
#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> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
typedef long long int ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL)
#define endl '\n'
#define pb push_back
#define conts continue
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define yes cout << "YES" << endl
#define no cout << "NO" << endl
#define ff first
#define ss second
#define ceil2(x,y) ((x+y-1) / (y))
#define sz(a) a.size()
#define setbits(x) __builtin_popcountll(x)
#ifndef ONLINE_JUDGE
#define debug(x) cout << #x <<" = "; print(x); cout << endl
#else
#define debug(x)
#endif
#define rep(i,n) for(int i = 0; i < n; ++i)
#define rep1(i,n) for(int i = 1; i <= n; ++i)
#define rev(i,s,e) for(int i = s; i >= e; --i)
#define trav(i,a) for(auto &i : a)
bool iseven(ll n) {if ((n & 1) == 0) return true; return false;}
void print(ll t) {cout << t;}
void print(int t) {cout << t;}
void print(string t) {cout << t;}
void print(char t) {cout << t;}
void print(double t) {cout << t;}
void print(ld t) {cout << t;}
template <class T, class V> void print(pair <T, V> p);
template <class T> void print(vector <T> v);
template <class T> void print(set <T> v);
template <class T, class V> void print(map <T, V> v);
template <class T> void print(multiset <T> v);
template <class T, class V> void print(pair <T, V> p) {cout << "{"; print(p.ff); cout << ","; print(p.ss); cout << "}";}
template <class T> void print(vector <T> v) {cout << "[ "; for (T i : v) {print(i); cout << " ";} cout << "]";}
template <class T> void print(set <T> v) {cout << "[ "; for (T i : v) {print(i); cout << " ";} cout << "]";}
template <class T> void print(multiset <T> v) {cout << "[ "; for (T i : v) {print(i); cout << " ";} cout << "]";}
template <class T, class V> void print(map <T, V> v) {cout << "[ "; for (auto i : v) {print(i); cout << " ";} cout << "]";}
template<typename T> void amin(T &a, T b) { a = min(a, b); }
template<typename T> void amax(T &a, T b) { a = max(a, b); }
void usaco(string filename) {
freopen((filename + ".in").c_str(), "r", stdin);
freopen((filename + ".out").c_str(), "w", stdout);
}
const int MOD = 1e9 + 7;
const int maxn = 1e5 + 5;
const int inf1 = 1e9 + 5;
const ll inf2 = ll(1e18) + 5;
template<typename T>
struct fenwick {
int siz;
vector<T> tree;
fenwick(int n) {
siz = n;
tree = vector<T>(n + 1);
}
int lsb(int x) {
return __builtin_ffs(x) - 1;
}
void build(vector<T> &a, int n) {
for (int i = 1; i <= n; ++i) {
int toadd = 1 << lsb(i);
int par = i + toadd;
tree[i] += a[i];
if (par <= siz) {
tree[par] += tree[i];
}
}
}
void pupd(int i, T v) {
while (i <= siz) {
tree[i] += v;
int toadd = 1 << lsb(i);
i += toadd;
}
}
T sum(int i) {
T res = 0;
while (i) {
res += tree[i];
int tosub = 1 << lsb(i);
i -= tosub;
}
return res;
}
T query(int l, int r) {
T res = sum(r) - sum(l - 1);
return res;
}
};
void solve(int test_case)
{
ll n; cin >> n;
vector<ll> a(n + 5);
rep1(i, n) cin >> a[i];
ll p; cin >> p;
rep1(i, n) a[i] -= p;
// count the no.of subarrays with sum >= 0
vector<ll> pre(n + 5);
rep1(i, n) pre[i] = pre[i - 1] + a[i];
auto b = pre;
sort(all(b));
auto it = unique(all(b));
b.resize(it - b.begin());
rep(i, n + 1) pre[i] = lower_bound(all(b), pre[i]) - b.begin() + 1;
ll ans = 0;
fenwick<ll> fenw(n + 5);
rep1(i, n) {
// i = right endpoint of subarray
fenw.pupd(pre[i - 1], 1);
ll cnt = fenw.query(1, pre[i]);
ans += cnt;
}
cout << ans << endl;
}
int main()
{
fastio;
int t = 1;
// cin >> t;
rep1(i, t) {
solve(i);
}
return 0;
}
Compilation message
vudu.cpp: In function 'void usaco(std::string)':
vudu.cpp:64:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
64 | freopen((filename + ".in").c_str(), "r", stdin);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
vudu.cpp:65:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
65 | freopen((filename + ".out").c_str(), "w", stdout);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
2 ms |
468 KB |
Output is correct |
| 2 |
Correct |
2 ms |
468 KB |
Output is correct |
| 3 |
Correct |
2 ms |
468 KB |
Output is correct |
| 4 |
Correct |
415 ms |
39860 KB |
Output is correct |
| 5 |
Correct |
217 ms |
17432 KB |
Output is correct |
| 6 |
Correct |
334 ms |
35364 KB |
Output is correct |
| 7 |
Correct |
385 ms |
36904 KB |
Output is correct |
| 8 |
Correct |
336 ms |
27076 KB |
Output is correct |
| 9 |
Correct |
392 ms |
41284 KB |
Output is correct |
| 10 |
Correct |
334 ms |
35788 KB |
Output is correct |
