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IDProblemSubmitterResultTimeMemoryLanguageFile sizeSubmit timeJudge time
#334545#8050. Random Permutationucup-team1055TL 1886ms6252kbC++143.5kb2024-02-22 04:15:572024-02-22 04:15:57

Judging History

你现在查看的是最新测评结果

  • [2024-02-22 04:15:57]
  • 评测
  • 测评结果:TL
  • 用时:1886ms
  • 内存:6252kb
  • [2024-02-22 04:15:57]
  • 提交

answer

#include <bits/stdc++.h>

#define rep(i, s, n) for (int i = (int)(s); i < (int)(n); i++)
#define rrep(i, s, n) for (int i = (int)(n)-1; i >= (int)(s); i--)
#define all(v) v.begin(), v.end()

using ll = long long;
using ld = long double;
using ull = unsigned long long;

template <typename T> bool chmin(T &a, const T &b) {
    if (a <= b) return false;
    a = b;
    return true;
}
template <typename T> bool chmax(T &a, const T &b) {
    if (a >= b) return false;
    a = b;
    return true;
}

using namespace std;

vector<int> random_permutation(int n){
	random_device seed_gen;
	mt19937 engine(seed_gen());
	vector<int> p(n);
	iota(p.begin(), p.end(), 1);
	shuffle(p.begin(), p.end(), engine);
	return p;
}

ll naive(int n, vector<int> p){
	ll ans = 0;
	rep(i,0,n){
		priority_queue<int, vector<int>, greater<int>> larger;
		priority_queue<int> smaller;
		rep(j,i,n){
			if (smaller.empty()){
				smaller.push(p[j]);
			}else if(larger.empty()){
				smaller.push(p[j]);
			}else if(larger.top() > p[j]){
				smaller.push(p[j]);
			}else{
				larger.push(p[j]);
			}
			while ((int)smaller.size() < (int)larger.size()){
				smaller.push(larger.top());
				larger.pop();
			}
			while ((int)smaller.size() > (int)larger.size() + 1){
				larger.push(smaller.top());
				smaller.pop();
			}
			ans += smaller.top();
		}
	}
	return ans;
}

const int mx = 1000;
const int mx_sub1 = 500;
const int mx_sub2 = 300;

ll fast(int n, vector<int> p){
	ll ans = 0;
	vector<int> left(2 * mx + 1);
	vector<int> right(2 * mx + 1);
	rep(i,0,n){
		fill(left.begin(), left.end(), 0);
		fill(right.begin(), right.end(), 0);
		int targ = p[i];
		{
			int cnt = mx;
			left[cnt]++;
			rrep(j,0,i){
				if (targ < p[j]) cnt--;
				else cnt++;
				if (abs(cnt - mx) > mx) break;
				left[cnt]++;
			}
		}
		{
			int cnt = mx + 1;
			right[cnt]++;
			rep(j,i+1,n){
				if (targ < p[j]) cnt--;
				else cnt++;
				if (abs(cnt - mx) > mx) break;
				right[cnt]++;
			}
		}
		ll var = 0;
		rep(j, 0, 2 * mx){
			var += (ll)right[2 * mx - j] * (left[j] + left[j + 1]);
		}
		ans += var * targ;
	}
	return ans;
}


ll fast2(int n, vector<int> p){
	ll ans = 0;
	vector<int> left(2 * mx + 1);
	vector<int> right(2 * mx + 1);
	vector<int> a(n, +1);
	
	vector<int> q(n);
	rep(i,0,n){
		q[p[i] - 1] = i;
	}
	reverse(q.begin(), q.end());

	for (int i: q){

		int targ = mx;
		if (min(n + 1 - p[i], p[i]) < n / 8){
			targ = mx_sub2;
		}else if (min(n + 1 - p[i], p[i]) < n / 4){
			targ = mx_sub1;
		}

		fill(left.begin() + mx - targ, left.begin() + mx + targ + 1, 0);
		fill(right.begin() + mx - targ, right.begin() + mx + targ + 1, 0);

		{
			int cnt = mx;
			left[cnt]++;
			rrep(j,0,i){
				cnt += a[j];
				if (abs(cnt - mx) > targ) break;
				left[cnt]++;
			}
		}

		{
			int cnt = mx + 1;
			right[cnt]++;
			rep(j,i+1,n){
				cnt += a[j];
				if (abs(cnt - mx) > targ) break;
				right[cnt]++;
			}
		}

		ll var = 0;
		rep(j, mx - targ, mx + targ - 1){
			var += (ll)right[2 * mx - j] * (left[j] + left[j + 1]);
		}
		ans += var * p[i];
		a[i] = -1;
	}

	return ans;
}

int main(){
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	
	//*
	int n; cin >> n;
	vector<int> p(n);
	rep(i,0,n){
		cin >> p[i];
	}
	//*/

	/*
	int n = 300000;
	vector<int> p = random_permutation(n);
	//*/
	
	//cout << naive(n, p) << endl;
	cout << fast2(n, p) << endl;
	//cout << fast(n, p) << endl;
}

Details

Tip: Click on the bar to expand more detailed information

Test #1:

score: 100
Accepted
time: 0ms
memory: 3608kb

input:

4
1 4 2 3

output:

22

result:

ok 1 number(s): "22"

Test #2:

score: 0
Accepted
time: 822ms
memory: 4704kb

input:

100000
56449 21738 74917 44834 36187 96576 37204 28451 3444 13029 66039 8955 51445 30706 27229 37159 66052 16691 70389 29935 44984 3648 75082 73600 76621 28345 5298 37940 49412 85260 92029 18185 84398 10233 79227 98312 96649 30680 65206 38879 75397 26951 11294 58085 37297 97167 59252 44104 4058 3796...

output:

250202478701074

result:

ok 1 number(s): "250202478701074"

Test #3:

score: 0
Accepted
time: 1886ms
memory: 6252kb

input:

200000
70900 189146 39056 135530 191967 133789 108558 81993 132081 113826 54456 127761 27836 64897 87159 105191 109446 81230 75525 90396 75756 50200 43091 151358 100791 193998 157161 119352 176873 120724 134471 155040 138534 182263 161855 4577 124893 199710 60764 146460 75314 43696 129155 64816 1390...

output:

1998651699409551

result:

ok 1 number(s): "1998651699409551"

Test #4:

score: -100
Time Limit Exceeded

input:

300000
291335 150122 292004 129126 26666 242892 124454 146198 257953 17400 245611 108131 68345 266915 44851 146376 110324 211968 251982 127849 152791 204625 213884 144643 137727 113838 115018 225220 169217 151 284989 29747 37230 110534 124886 224954 253706 175150 103605 289983 165895 113248 32809 28...

output:

6755672893227829

result: