Submission #924388

#	Time	Username	Problem	Language	Result	Execution time	Memory
924388		TIN	Vudu (COCI15_vudu)	C++17	112 / 140	472 ms	65536 KiB

vudu

#include <bits/stdc++.h>

using namespace std;

#define FNAME "test"

typedef long long ll;

const int N = 1e6 + 1000;

int n;
ll a[N];
ll P;
vector<ll> pre;
ll ans;

struct Fenwick {
	int n;
	vector<ll> f;

	Fenwick(int n) : n(n), f(n + 1, 0) {}

	void set(int i) {
		for (; i <= n; i += i & (-i)) f[i]++;
		return;
	}

	ll get(int i) {
		ll r = 0;
		for (; i >= 1; i -= i & (-i)) r += f[i];
		return r;
	}
};

void Task() {
	ios_base::sync_with_stdio(false);
	cin.tie(0); cout.tie(0);
	cout << fixed << setprecision(9);
	if (fopen(FNAME".inp","r")) {
		freopen(FNAME".inp","r",stdin);
		freopen(FNAME".out","w",stdout);
	}
}

void compress(vector<ll>& v) {
	set<ll> s(v.begin(), v.end());
	vector<ll> b(s.begin(), s.end());
	for (ll &x : v) x = lower_bound(b.begin(), b.end(), x) - b.begin() + 1;
	return;
}

void Solve() {
	//Your Code
	cin >> n;
	for (int i = 1; i <= n; i++) cin >> a[i];
	cin >> P;
	pre.resize(n + 1);
	pre[0] = 0;
	for (int i = 1; i <= n; i++) pre[i] = pre[i - 1] + (a[i] - P);
	compress(pre);
	Fenwick BIT(N);
	ans = 0;
	for (int i = 1; i <= n; i++) {
		BIT.set(pre[i - 1]);
		ans += BIT.get(pre[i]);
	}
	cout << ans << '\n';
	return;
}

int main() {
	Task();
	Solve();
	cerr << "\nTime run: " << 1000*clock()/CLOCKS_PER_SEC << "ms";
	return 37^37;
}

Compilation message (stderr)

vudu.cpp: In function 'void Task()':
vudu.cpp:40:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   40 |   freopen(FNAME".inp","r",stdin);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
vudu.cpp:41:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   41 |   freopen(FNAME".out","w",stdout);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 112 / 140