CSES - Datatähti Open 2021 - Results
Submission details
Task:Sorting
Sender:teehandsome
Submission time:2021-01-31 17:22:19 +0200
Language:C++11
Status:READY
Result:0
Feedback
groupverdictscore
#10
#20
Test results
testverdicttimegroup
#10.01 s1, 2details
#20.01 s2details
#30.01 s1, 2details
#40.01 s1, 2details

Code

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#define endl '\n'
#define INF 1e9+7
#define all(x) x.begin(),x.end()
using namespace std;
using namespace __gnu_pbds;
using ll=long long;
using pii=pair<int,int>;
using ppi=pair<int,pii>;
using oset=tree<int,null_type,less<int>,rb_tree_tag,tree_order_statistics_node_update>;

template<typename T>
void _print(vector<T> x) {cerr<<"{"; for(auto e:x) cerr<<e<<","; cerr<<"}";}
void _print(pii x) {cerr<<"{"<<x.first<<","<<x.second<<"}";}
template<typename T>
void _print(T x) {cerr<<x;}

void dbg() {cerr<<endl;}
template<typename Head,typename... Tail>
void dbg(Head H,Tail... T) {
    _print(H);
    if(sizeof...(T)) cerr<<",";
    else cerr<<"\"]";
    dbg(T...);
}
#define debug(...) cerr<<"["<<#__VA_ARGS__<<"]:[\"",dbg(__VA_ARGS__)

int n;
vector<int> a,pos;

int main () {
    ios::sync_with_stdio(false); cin.tie(0);
    int t; cin>>t;
    while(t--) {
        cin>>n; a.resize(n+1),pos.resize(n+1);
        for(int i=1;i<=n;i++) {
            cin>>a[i]; pos[a[i]]=i;
        }
        for(int i=1;i<=n;i++) {
            int p=pos[i];
            if(p==i) continue;
            if(p<i or p==i+1 or p==n) {
                cout<<"NO"<<endl; goto newT;
            }
            swap(pos[a[i]],pos[a[p]]);
            swap(pos[a[i+1]],pos[a[p+1]]);
            swap(a[i],a[p]);
            swap(a[i+1],a[p+1]);

        }
        for(int i=1;i<=n;i++) {
            if(a[i]!=i) {
                cout<<"NO"<<endl; goto newT;
            }
        }
        cout<<"YES"<<endl;
        newT:;
    }
}

Test details

Test 1

Group: 1, 2

Verdict:

input
153
1
1
2
1 2
...

correct output
YES
YES
NO
NO
NO
...

user output
YES
YES
NO
NO
NO
...

Test 2

Group: 2

Verdict:

input
1000
59
35 29 32 50 11 15 9 21 19 45 2...

correct output
YES
NO
YES
NO
YES
...

user output
NO
NO
NO
NO
NO
...

Test 3

Group: 1, 2

Verdict:

input
720
6
1 6 4 5 2 3
6
6 3 2 1 5 4
...

correct output
YES
NO
NO
NO
YES
...

user output
NO
NO
NO
NO
NO
...

Test 4

Group: 1, 2

Verdict:

input
1000
8
7 4 2 8 6 3 5 1
8
3 8 2 7 5 4 6 1
...

correct output
NO
NO
YES
NO
YES
...

user output
NO
NO
NO
NO
NO
...