CSES - Putka Open 2020 – 1/5 - Results
Submission details
Task:Vaihdot
Sender:Sisuaski
Submission time:2020-09-06 04:58:35 +0300
Language:C++11
Status:READY
Result:100
Feedback
groupverdictscore
#1ACCEPTED13
#2ACCEPTED23
#3ACCEPTED64
Test results
testverdicttimegroup
#1ACCEPTED0.02 s1, 2, 3details
#2ACCEPTED0.01 s1, 2, 3details
#3ACCEPTED0.01 s1, 2, 3details
#4ACCEPTED0.02 s1, 2, 3details
#5ACCEPTED0.01 s1, 2, 3details
#6ACCEPTED0.01 s1, 2, 3details
#7ACCEPTED0.01 s1, 2, 3details
#8ACCEPTED0.01 s1, 2, 3details
#9ACCEPTED0.02 s2, 3details
#10ACCEPTED0.02 s2, 3details
#11ACCEPTED0.02 s2, 3details
#12ACCEPTED0.02 s2, 3details
#13ACCEPTED0.02 s2, 3details
#14ACCEPTED0.02 s2, 3details
#15ACCEPTED0.02 s2, 3details
#16ACCEPTED0.02 s2, 3details
#17ACCEPTED0.14 s3details
#18ACCEPTED0.51 s3details
#19ACCEPTED0.08 s3details
#20ACCEPTED0.08 s3details
#21ACCEPTED0.08 s3details
#22ACCEPTED0.10 s3details
#23ACCEPTED0.49 s3details
#24ACCEPTED0.68 s3details

Code

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
typedef long long ll;
typedef pair<int,int> P;

const int MN = 2<<17;
int ord[MN];
int pos[MN];
bool isOk(int i) {
	if (pos[i-1] < pos[i+1]) return pos[i]>pos[i-1] && pos[i]<pos[i+1];
	return pos[i]<pos[i+1] || pos[i]>pos[i-1];
}

vector<int> tree[2*MN];
P best = {0,0};

void add(int a, int b, int x) {
	for(a+=MN, b+=MN; a<=b; a/=2, b/=2) {
		if (a&1) tree[a++].push_back(x);
		if (~b&1) tree[b--].push_back(x);
	}
}

int count(int n, int f, int t) {
	int res=0;
	int n0 = n;
	for(n+=MN; n>=1; n/=2) {
		auto a = lower_bound(tree[n].begin(), tree[n].end(), f);
		auto b = upper_bound(tree[n].begin(), tree[n].end(), t);
		res += b-a;
		if (a != b) best = {n0, *a};
	}
	return res;
}

void doSwap(int a, int b) {
	swap(ord[a], ord[b]);
	swap(pos[ord[a]], pos[ord[b]]);
}
bool isGoodSwap(int i) {
	int fst = (pos[i-1] < pos[i]) + (pos[i] < pos[i+1]) + (pos[i+1] < pos[i+2]);
	swap(pos[i], pos[i+1]);
	int snd = (pos[i-1] < pos[i]) + (pos[i] < pos[i+1]) + (pos[i+1] < pos[i+2]);
	swap(pos[i], pos[i+1]);
	return snd > fst;
}

void addIdx(int i, int n, int offset=0) {
	if (pos[i-1] < pos[i+1]) {
		add(pos[i-1]+offset, pos[i+1]-offset, pos[i]);
	} else {
		add(1, pos[i+1]-offset, pos[i]);
		add(pos[i-1]+offset, n, pos[i]);
	}
}

int getCnt(int i, int n) {
	if (pos[i-1] < pos[i+1]) {
		int x = count(pos[i], pos[i-1]+1, pos[i+1]-1);
		return x;
	} else {
		int x = count(pos[i], 1, pos[i+1]-1);
		int y = count(pos[i], pos[i-1]+1, n);
		return x+y;
	}
}

int main() {
	int n;cin>>n;
	for(int i=1; i<=n; ++i) cin>>ord[i];
	for(int i=1; i<=n; ++i) pos[ord[i]] = i;
	pos[n+1] = n+1;
	for(int i=1; i<=n; ++i) if (!isOk(i)) addIdx(i, n);
	for(auto& t: tree) sort(t.begin(), t.end());
	ll cnt = 0;
	for(int i=1; i<=n; ++i) if (!isOk(i)) cnt += getCnt(i, n);
	cnt /= 2;

	if (cnt == 0) {
		for(int i=1; i<=n; ++i) {
			if (isOk(i)) continue;
			int x = count(pos[i], 1, n);
			cnt += x;
		}
		for(int i=1; i<n; ++i) {
			if (isGoodSwap(i)) --cnt;
		}

		for(int i=1; i<=n; ++i) if (isOk(i)) cnt += getCnt(i, n);
	}
	if (cnt == 0) {

		for(int i=1; i<=n; ++i) {
			if (isOk(i)) {
				int x = count(pos[i], 1, n);
				cnt += x;
			}
		}

		for(auto& t: tree) t.clear();
		for(int i=1; i<=n; ++i) if (isOk(i)) addIdx(i, n, 1);
		int bcnt = 0;
		for(int i=1; i<=n; ++i) if (!isOk(i)) bcnt++;
		cnt += bcnt * (bcnt-1) / 2;
		for(auto& t: tree) sort(t.begin(), t.end());
		int okc = 0;
		for(int i=1; i<=n; ++i) {
			if (isOk(i)) {
				okc += getCnt(i, n);
				okc--;
			} else {
				int x = count(pos[i], 1, n);
				cnt += x;
			}
		}
		cnt += okc / 2;
		for(int i=1; i<n; ++i) {
			if (isOk(i) && isOk(i+1) && isGoodSwap(i)) {
				++cnt;
			}
		}
	}
	if (cnt == 0) {
		cnt = n-1;
		best = {1,2};
	}

	doSwap(best.first, best.second);

	int res=0;
	for(int i=1; i<=n; ++i) {
		if (i==1 || pos[i]<pos[i-1]) res++;
	}
	cout<<res<<' '<<cnt<<'\n';
}

Test details

Test 1

Group: 1, 2, 3

Verdict: ACCEPTED

input
100
1 2 3 4 5 6 7 8 9 10 11 12 13 ...

correct output
2 99

user output
2 99

Test 2

Group: 1, 2, 3

Verdict: ACCEPTED

input
100
100 99 98 97 96 95 94 93 92 91...

correct output
98 4851

user output
98 4851

Test 3

Group: 1, 2, 3

Verdict: ACCEPTED

input
100
1 2 88 4 5 6 7 8 9 10 11 12 13...

correct output
16 5

user output
16 5

Test 4

Group: 1, 2, 3

Verdict: ACCEPTED

input
100
51 48 74 70 45 71 24 88 55 99 ...

correct output
49 131

user output
49 131

Test 5

Group: 1, 2, 3

Verdict: ACCEPTED

input
100
45 67 29 62 70 77 41 74 52 95 ...

correct output
52 268

user output
52 268

Test 6

Group: 1, 2, 3

Verdict: ACCEPTED

input
100
47 98 2 75 6 21 84 8 4 89 27 9...

correct output
48 149

user output
48 149

Test 7

Group: 1, 2, 3

Verdict: ACCEPTED

input
100
73 68 17 94 71 63 61 13 58 10 ...

correct output
47 116

user output
47 116

Test 8

Group: 1, 2, 3

Verdict: ACCEPTED

input
100
17 16 45 94 6 1 36 81 31 13 51...

correct output
45 95

user output
45 95

Test 9

Group: 2, 3

Verdict: ACCEPTED

input
5000
1 2 3 4 5 6 7 8 9 10 11 12 13 ...

correct output
2 4999

user output
2 4999

Test 10

Group: 2, 3

Verdict: ACCEPTED

input
5000
5000 4999 4998 4997 4996 4995 ...

correct output
4998 12492501

user output
4998 12492501

Test 11

Group: 2, 3

Verdict: ACCEPTED

input
5000
1 2 3 4 5 6 7 8 9 10 11 12 13 ...

correct output
19 10

user output
19 10

Test 12

Group: 2, 3

Verdict: ACCEPTED

input
5000
1 2 3 4 5 6 264 8 9 10 11 12 1...

correct output
190 96

user output
190 96

Test 13

Group: 2, 3

Verdict: ACCEPTED

input
5000
1 2 3 4 5 6 7 8 9 2400 11 12 1...

correct output
1378 27938

user output
1378 27938

Test 14

Group: 2, 3

Verdict: ACCEPTED

input
5000
4012 2 4820 4208 1868 1728 362...

correct output
2511 436307

user output
2511 436307

Test 15

Group: 2, 3

Verdict: ACCEPTED

input
5000
3877 3972 1112 3669 1959 4640 ...

correct output
2497 417065

user output
2497 417065

Test 16

Group: 2, 3

Verdict: ACCEPTED

input
5000
2774 998 4525 2884 487 1995 41...

correct output
2518 426448

user output
2518 426448

Test 17

Group: 3

Verdict: ACCEPTED

input
200000
1 2 3 4 5 6 7 8 9 10 11 12 13 ...

correct output
2 199999

user output
2 199999

Test 18

Group: 3

Verdict: ACCEPTED

input
200000
200000 199999 199998 199997 19...

correct output
199998 19999700001

user output
199998 19999700001

Test 19

Group: 3

Verdict: ACCEPTED

input
200000
1 2 3 4 5 6 7 8 9 10 11 12 13 ...

correct output
19 10

user output
19 10

Test 20

Group: 3

Verdict: ACCEPTED

input
200000
1 2 3 4 5 6 7 8 9 10 11 12 13 ...

correct output
199 100

user output
199 100

Test 21

Group: 3

Verdict: ACCEPTED

input
200000
1 2 3 4 5 6 7 8 9 10 11 12 13 ...

correct output
1979 1030

user output
1979 1030

Test 22

Group: 3

Verdict: ACCEPTED

input
200000
1 2 184153 4 5 6 7 8 164545 10...

correct output
18081 477187

user output
18081 477187

Test 23

Group: 3

Verdict: ACCEPTED

input
200000
151013 68675 119105 58292 3335...

correct output
86328 318722426

user output
86328 318722426

Test 24

Group: 3

Verdict: ACCEPTED

input
200000
11562 33356 106752 170825 2723...

correct output
99873 663048119

user output
99873 663048119