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Submission #291299

# Submission time Handle Problem Language Result Execution time Memory
291299 2020-09-05T05:12:18 Z eggag32 Fancy Fence (CEOI20_fancyfence) C++17
100 / 100
 130 ms 9848 KB 
#pragma GCC optimize ("O3")
#pragma GCC target ("sse4")
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
typedef vector<int> vi;
typedef pair<int, int> pi;
#define debug(x) cerr << #x << ": " << x << endl
#define debug2(x, y) debug(x), debug(y)
#define repn(i, a, b) for(int i = (int)(a); i < (int)(b); i++)
#define rep(i, a) for(int i = 0; i < (int)(a); i++)
#define all(v) v.begin(), v.end() 
#define mp make_pair
#define pb push_back
#define lb lower_bound
#define ub upper_bound
#define fi first
#define se second
#define sq(x) ((x) * (x))
const int MOD = 1e9 + 7;
const int mxN = 1e5 + 5;

template<class T> T gcd(T a, T b){ return ((b == 0) ? a : gcd(b, a % b)); }

bool cmp(pair<ll, pair<ll, ll>> a, pair<ll, pair<ll, ll>> b){
	return a.se.fi < b.se.fi;
}

template<class T> struct BIT{
	vector<T> bit;
	BIT(){
		bit.assign(mxN, 0);
	}
	void update(int ind, T delta){
		for(; ind < mxN; ind = ind | (ind + 1)){
			bit[ind] += delta;
		}
	}
	T query(int ind){
		T sum = 0;
		for(; ind >= 0; ind = (ind & (ind + 1)) - 1){
			sum += bit[ind];
		}
		return sum;
	}
};

int main(){
	ios_base::sync_with_stdio(false);
	cin.tie(0);
	//freopen("input1.txt", "r", stdin);
	//freopen("output.out", "w", stdout);
	int n;
	cin >> n;
	vector<pair<ll, pair<ll, ll>>> p(n);
	vector<ll> w(n), h(n);
	rep(i, n) cin >> p[i].se.fi, p[i].fi = i, h[i] = p[i].se.fi;
	rep(i, n) cin >> p[i].se.se, w[i] = p[i].se.se, h[i]++;
	sort(all(p), cmp);
	BIT<ll> bit;
	rep(i, n) bit.update(i, w[i]);
	ll ans = 0LL;
	set<ll> pos;
	rep(i, n){
		//inside
		ll mn = h[p[i].fi];
		ll one = ((mn * (mn - 1)) / 2) % MOD;
		ll two = ((w[p[i].fi] * (w[p[i].fi] + 1)) / 2) % MOD;
		ll add = (one * two) % MOD;
		(ans += add) %= MOD;
		ll sub = 0LL, sub1 = 0LL;
		auto it1 = pos.lb(p[i].fi);
		int f1 = 0;
		if(it1 != pos.begin()) it1--, f1 = 1;
		if(pos.size() && f1) sub = bit.query(*it1); //we have smth before
		ll left = (p[i].fi ? bit.query(p[i].fi - 1) : 0LL) - sub; //how many on left are below
		auto it = pos.lb(p[i].fi);
		int f = 0;
		if(it != pos.end()){
			f = 1;
			sub1 = bit.query(*it - 1);
		}
		ll right = (f ? sub1 : bit.query(mxN - 1)) - bit.query(p[i].fi); //how many on right are below
		//left - right
		add = ((((left % MOD) * (right % MOD)) % MOD) * one) % MOD;
		(ans += add) %= MOD;
		//left - us
		add = ((((left % MOD) * (w[p[i].fi] % MOD)) % MOD) * one) % MOD;
		(ans += add) %= MOD;
		//us - right
		add = ((((w[p[i].fi] % MOD) * (right % MOD)) % MOD) * one) % MOD;
		(ans += add) %= MOD;
		bit.update(p[i].fi, -w[p[i].fi]);
		pos.insert(p[i].fi);
	}
	cout << ans << endl;
	return 0;
}
/*
Things to look out for:
	- Integer overflows
	- Array bounds
	- Special cases
Be careful!
*/

Subtask #1
0.0 / 0.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 1152 KB Output is correct
2 Correct 2 ms 1280 KB Output is correct

Subtask #2
12.0 / 12.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 1152 KB Output is correct
2 Correct 1 ms 1152 KB Output is correct
3 Correct 1 ms 1152 KB Output is correct
4 Correct 1 ms 1152 KB Output is correct
5 Correct 1 ms 1152 KB Output is correct

Subtask #3
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 1152 KB Output is correct
2 Correct 2 ms 1152 KB Output is correct
3 Correct 39 ms 5376 KB Output is correct
4 Correct 79 ms 9720 KB Output is correct
5 Correct 83 ms 9720 KB Output is correct
6 Correct 77 ms 9720 KB Output is correct

Subtask #4
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 1280 KB Output is correct
2 Correct 8 ms 2048 KB Output is correct
3 Correct 39 ms 5496 KB Output is correct
4 Correct 77 ms 9720 KB Output is correct
5 Correct 88 ms 9688 KB Output is correct
6 Correct 1 ms 1152 KB Output is correct

Subtask #5
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 1152 KB Output is correct
2 Correct 2 ms 1280 KB Output is correct
3 Correct 8 ms 2048 KB Output is correct
4 Correct 39 ms 5496 KB Output is correct
5 Correct 78 ms 9720 KB Output is correct
6 Correct 80 ms 9720 KB Output is correct
7 Correct 1 ms 1280 KB Output is correct
8 Correct 8 ms 2048 KB Output is correct
9 Correct 41 ms 5644 KB Output is correct
10 Correct 84 ms 9692 KB Output is correct
11 Correct 85 ms 9720 KB Output is correct
12 Correct 1 ms 1152 KB Output is correct

Subtask #6
18.0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 1152 KB Output is correct
2 Correct 2 ms 1152 KB Output is correct
3 Correct 1 ms 1152 KB Output is correct
4 Correct 1 ms 1152 KB Output is correct
5 Correct 1 ms 1152 KB Output is correct
6 Correct 1 ms 1152 KB Output is correct
7 Correct 1 ms 1152 KB Output is correct
8 Correct 2 ms 1152 KB Output is correct
9 Correct 2 ms 1152 KB Output is correct
10 Correct 2 ms 1152 KB Output is correct
11 Correct 1 ms 1152 KB Output is correct
12 Correct 1 ms 1152 KB Output is correct
13 Correct 2 ms 1280 KB Output is correct
14 Correct 2 ms 1152 KB Output is correct
15 Correct 2 ms 1152 KB Output is correct
16 Correct 1 ms 1152 KB Output is correct

Subtask #7
27.0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 1152 KB Output is correct
2 Correct 2 ms 1280 KB Output is correct
3 Correct 1 ms 1152 KB Output is correct
4 Correct 2 ms 1152 KB Output is correct
5 Correct 1 ms 1152 KB Output is correct
6 Correct 1 ms 1152 KB Output is correct
7 Correct 1 ms 1152 KB Output is correct
8 Correct 1 ms 1152 KB Output is correct
9 Correct 1 ms 1152 KB Output is correct
10 Correct 2 ms 1152 KB Output is correct
11 Correct 39 ms 5496 KB Output is correct
12 Correct 77 ms 9848 KB Output is correct
13 Correct 82 ms 9720 KB Output is correct
14 Correct 81 ms 9760 KB Output is correct
15 Correct 2 ms 1280 KB Output is correct
16 Correct 8 ms 2048 KB Output is correct
17 Correct 38 ms 5496 KB Output is correct
18 Correct 83 ms 9720 KB Output is correct
19 Correct 84 ms 9720 KB Output is correct
20 Correct 2 ms 1280 KB Output is correct
21 Correct 8 ms 2048 KB Output is correct
22 Correct 41 ms 5372 KB Output is correct
23 Correct 84 ms 9720 KB Output is correct
24 Correct 87 ms 9720 KB Output is correct
25 Correct 1 ms 1152 KB Output is correct
26 Correct 2 ms 1152 KB Output is correct
27 Correct 2 ms 1280 KB Output is correct
28 Correct 2 ms 1152 KB Output is correct
29 Correct 2 ms 1152 KB Output is correct
30 Correct 10 ms 2048 KB Output is correct
31 Correct 11 ms 2048 KB Output is correct
32 Correct 54 ms 5496 KB Output is correct
33 Correct 59 ms 5368 KB Output is correct
34 Correct 129 ms 9720 KB Output is correct
35 Correct 126 ms 9720 KB Output is correct
36 Correct 130 ms 9848 KB Output is correct
37 Correct 124 ms 9720 KB Output is correct
38 Correct 1 ms 1280 KB Output is correct
39 Correct 125 ms 9688 KB Output is correct
40 Correct 113 ms 9720 KB Output is correct
41 Correct 89 ms 9720 KB Output is correct
42 Correct 85 ms 9724 KB Output is correct