제출 #547701

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
547701		SmolBrain	Vudu (COCI15_vudu)	C++17	140 / 140	415 ms	41284 KiB

vudu

// 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;
}

컴파일 시 표준 에러 (stderr) 메시지

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);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 140 / 140