제출 #1275328

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1275328		chanhchuong123	Index (COCI21_index)	C++20	110 / 110	481 ms	8508 KiB

index

#include<bits/stdc++.h>
using namespace std;

const bool multiTest = false;
#define task "C"
#define fi first
#define se second
#define MASK(i) (1LL << (i))
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define BIT(mask, i) ((mask) >> (i) & 1)

template<typename T1, typename T2> bool minimize(T1 &a, T2 b) {
	if (a > b) a = b; else return 0; return 1;
}
template<typename T1, typename T2> bool maximize(T1 &a, T2 b) {
	if (a < b) a = b; else return 0; return 1;
}

const int MAX = 200020;
int n, q, nAsk;
int pp[MAX];
int ll[MAX];
int rr[MAX];
int ps[MAX];
int l[MAX];
int r[MAX];
pair<int, int> queries[MAX];

struct FenwickTree {
    vector<int> bit;
    int n;

    FenwickTree(int _n = 0) {
        n = _n;
        bit.assign(_n + 5, 0);
    }

    void update(int id, int delta) {
        for (; id <= n; id += id & -id)
            bit[id] += delta;
    }

    int get(int id) {
        int res = 0;
        for (; id > 0; id -= id & -id)
            res += bit[id];
        return res;
    }

    int get(int l, int r) {
        return get(r) - get(l - 1);
    }
};

void solve(void) {
    sort(queries + 1, queries + 1 + nAsk);
    FenwickTree bit(n);
    for (int i = nAsk, j = 1; i >= 1; --i) {
        int idQuery = queries[i].se;
        while (j <= n && pp[ps[j]] >= queries[i].fi) bit.update(ps[j++], +1);
        if (bit.get(l[idQuery], r[idQuery]) >= queries[i].fi) ll[idQuery] = queries[i].fi; else rr[idQuery] = queries[i].fi;
    }
}

/*
7 6
3 2 3 1 1 4 7
3 4
1 7
1 6
4 5
1 2
5 7
*/

void process(void) {
    cin >> n >> q;
    for (int i = 1; i <= n; ++i) {
        cin >> pp[i];
        ps[i] = i;
    }
    sort(ps + 1, ps + 1 + n, [](int u, int v) {
        return pp[u] > pp[v];
    });

    for (int i = 1; i <= q; ++i) {
        cin >> l[i] >> r[i];
        ll[i] = 1;
        rr[i] = n + 1;
    }

    for (int t = 0; t < 20; ++t) {
        nAsk = 0;
        for (int i = 1; i <= q; ++i) if (rr[i] - ll[i] > 1) {
            int mid = ll[i] + rr[i] >> 1;
            queries[++nAsk] = make_pair(mid, i);
        }
        solve();
    }

    for (int i = 1; i <= q; ++i) {
        cout << ll[i] << '\n';
    }
}

int main(void) {
	ios_base::sync_with_stdio(false); cin.tie(nullptr); cout.tie(nullptr);
	if (fopen(task".inp", "r")) {
		freopen(task".inp", "r",  stdin);
		freopen(task".out", "w", stdout);
	}

	int nTest = 1; if (multiTest) cin >> nTest;
	while (nTest--) {
		process();
	}

	return 0;
}

컴파일 시 표준 에러 (stderr) 메시지

index.cpp: In function 'int main()':
index.cpp:110:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  110 |                 freopen(task".inp", "r",  stdin);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
index.cpp:111:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  111 |                 freopen(task".out", "w", stdout);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 20 / 20
• Subtask 2: 40 / 40
• Subtask 3: 50 / 50