Submission #929853

#	Time	Username	Problem	Language	Result	Execution time	Memory
929853		FanOfWilliamLin	Growing Trees (BOI11_grow)	C++14	100 / 100	108 ms	3392 KiB

grow

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

#define N 100000

int n, q, a[N], bit[N];

void add(int l, int r, int x) {  // add x to [l, r]
	if (r < l) return;
	for (; l < n; l |= l + 1) bit[l] += x;
	for (++r; r < n; r |= r + 1) bit[r] -= x;
}
int query(int i) {  // point query at i
	int sum = 0;
	for (; i >= 0; i &= i + 1, --i) sum += bit[i];
	return sum;
}

template <class T, class U> T firstTrue(T lo, T hi, U f) {
	assert(lo <= hi);
	++hi;              // assuming f is increasing
	while (lo < hi) {  // find first index such that f is true
		T mid = lo + (hi - lo) / 2;
		f(mid) ? hi = mid : lo = mid + 1;
	}
	return lo;
}

int main() {
	ios::sync_with_stdio(false);
	cin.tie(NULL);

	cin >> n >> q;
	for (int i = 0; i < n; ++i) cin >> a[i];
	sort(a, a + n);
	for (int i = 0; i < n; ++i) add(i, i, a[i]);
	for (int i = 0; i < q; ++i) {
		char c;
		int a, b;

		cin >> c >> a >> b;
		if (c == 'F') {
			int l = firstTrue(0, n - 1, [&](int i) { return query(i) >= b; });
			if (l == n)  // found nothing
				continue;
			int r = l + a - 1;
			if (r >= n - 1) {
				add(l, n - 1, 1);
				continue;
			}
			int x = query(r);
			int l_ = firstTrue(l, n - 1, [&](int i) { return query(i) >= x; });
			int r_ =
			    firstTrue(l_, n - 1, [&](int i) { return query(i) > x; }) - 1;
			add(l, l_ - 1, 1);
			add(r_ - (a - (l_ - l)) + 1, r_, 1);
		} else {
			int l = firstTrue(0, n - 1, [&](int i) { return query(i) >= a; });
			int r = firstTrue(0, n - 1, [&](int i) { return query(i) > b; });
			cout << r - l << '\n';
		}
	}
}

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 10 / 10
• Subtask 4: 10 / 10
• Subtask 5: 10 / 10
• Subtask 6: 10 / 10
• Subtask 7: 10 / 10
• Subtask 8: 10 / 10
• Subtask 9: 10 / 10
• Subtask 10: 10 / 10