Submission #1112174

#	Time	Username	Problem	Language	Result	Execution time	Memory
1112174		farica	Sails (IOI07_sails)	C++14	100 / 100	67 ms	3064 KiB

sails

#include <bits/stdc++.h>

using namespace std;

const int N = 1e5 + 5;

template <class T> class BIT {
  private:
	int size;
	vector<T> bit;
	vector<T> arr;

  public:
	BIT(int size) : size(size), bit(size + 1), arr(size) {}

	void set(int ind, T val) { add(ind, val - arr[ind]); }

	void add(int ind, T val) {
		arr[ind] += val;
		ind++;
		for (; ind <= size; ind += ind & -ind) { bit[ind] += val; }
	}

	T pref_sum(int ind) {
		ind++;
		T total = 0;
		for (; ind > 0; ind -= ind & -ind) { total += bit[ind]; }
		return total;
	}
};

void solve() {
    int n;
    cin >> n;
    vector<pair<int,int>>v(n);
    for(int i=0; i<n; ++i) cin >> v[i].first >> v[i].second;
    sort(v.begin(), v.end());
    BIT<int> bit(N);
    const auto first = [&](int val, int r) {
        int l = 0;
        while(l < r) {
            int mid = l + (r - l) / 2, x = bit.pref_sum(mid);
            if(x < val) r = mid;
            else l = mid + 1;
        }
        return l;
    };
    for(int i=0; i<n; ++i) {
        int len = v[i].first - v[i].second, val = bit.pref_sum(len), x = first(val, v[i].first), y = first(val+1, v[i].first);
        bit.add(x, 1);
        bit.add(v[i].first, -1);
        bit.add(y, 1);
        bit.add(y + v[i].second - (v[i].first - x), -1);
    }
    long long ans = 0;
    for(int i=0; i<N; ++i) {
        int tmp = bit.pref_sum(i);
        ans += 1ll * tmp * (tmp-1) / 2;
    }
    cout << ans << endl;
}

signed main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0); cout.tie(0);

    int t = 1;
    while(t--) solve();

    return 0;
}

• Subtask 1: 5 / 5
• Subtask 2: 10 / 10
• Subtask 3: 10 / 10
• Subtask 4: 5 / 5
• Subtask 5: 10 / 10
• Subtask 6: 10 / 10
• Subtask 7: 10 / 10
• Subtask 8: 10 / 10
• Subtask 9: 10 / 10
• Subtask 10: 10 / 10
• Subtask 11: 10 / 10