oj.uz

Submission #398492

# Submission time Handle Problem Language Result Execution time Memory
398492 2021-05-04T11:47:55 Z MarcoMeijer Cat (info1cup19_cat) C++14
18 / 100
 573 ms 14100 KB 
#include <bits/stdc++.h>
using namespace std;
 
// macros
typedef long long ll;
typedef long double ld;
typedef pair<int, int> ii;
typedef pair<ll, ll> lll;
typedef tuple<int, int, int> iii;
typedef vector<int> vi;
typedef vector<ii> vii;
typedef vector<iii> viii;
typedef vector<ll> vll;
typedef vector<lll> vlll;
#define REP(a,b,c) for(int a=int(b); a<int(c); a++)
#define RE(a,c) REP(a,0,c)
#define RE1(a,c) REP(a,1,c+1)
#define REI(a,b,c) REP(a,b,c+1)
#define REV(a,b,c) for(int a=int(c-1); a>=int(b); a--)
#define FOR(a,b) for(auto& a : b)
#define all(a) a.begin(), a.end()
#define INF 1e18
#define EPS 1e-9
#define pb push_back
#define popb pop_back
#define fi first
#define se second
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
 
// input
template<class T> void IN(T& x) {cin >> x;}
template<class H, class... T> void IN(H& h, T&... t) {IN(h); IN(t...); }
 
// output
template<class T1, class T2> void OUT(const pair<T1,T2>& x);
template<class T> void OUT(const vector<T>& x);
template<class T> void OUT(const T& x) {cout << x;}
template<class H, class... T> void OUT(const H& h, const T&... t) {OUT(h); OUT(t...); }
template<class T1, class T2> void OUT(const pair<T1,T2>& x) {OUT(x.fi,' ',x.se);}
template<class T> void OUT(const vector<T>& x) {RE(i,x.size()) OUT(i==0?"":" ",x[i]);}
template<class... T> void OUTL(const T&... t) {OUT(t..., "\n"); }
template<class H> void OUTLS(const H& h) {OUTL(h); }
template<class H, class... T> void OUTLS(const H& h, const T&... t) {OUT(h,' '); OUTLS(t...); }
 
// dp
template<class T> bool ckmin(T&a, T&b) { bool bl = a > b; a = min(a,b); return bl;}
template<class T> bool ckmax(T&a, T&b) { bool bl = a < b; a = max(a,b); return bl;}
 
void program();
int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    program();
}
 
 
//===================//
//   begin program   //
//===================//
 
const int MX = 5e5;
const int N = (1<<20);

int testCases;
int n, a[MX], ra[MX];

void program() {
    IN(testCases);
    while(testCases--) {
        IN(n);
        RE1(i,n) IN(a[i]);
        RE1(i,n) ra[a[i]] = i;

        bool possible = true;
        RE1(i,n) if(a[i] + a[n-i+1] != n+1) possible = false;

        vii ans;
        auto makeSwap = [&](int x, int y) {
            swap(a[x],a[y]);
            swap(a[n-x+1], a[n-y+1]);
            ra[a[x]] = x;
            ra[a[n-x+1]] = n-x+1;
            ra[a[y]] = y;
            ra[a[n-y+1]] = n-y+1;
            ans.pb({x,y});
        };

        RE1(i,n) if(a[i] != i) {
            makeSwap(i,a[i]);
        }

        vi wrongSide;
        RE1(i,n/2) if(a[i] > n/2) wrongSide.pb(i);

        if(wrongSide.size()%2) possible = false;

        if(!possible) {
            OUTL(-1);
            continue;
        }

        RE(i,wrongSide.size()) {
            makeSwap(wrongSide[i], wrongSide[i+1]);
            makeSwap(wrongSide[i], n-wrongSide[i+1]+1);
            i++;
        }

        OUTLS(ans.size(),ans.size());
        FOR(p,ans) OUTL(p);
    }
}

Subtask #1
5.25 / 15.0

# Verdict Execution time Memory Grader output
1 Partially correct 6 ms 460 KB Valid reconstruction

Subtask #2
1.5 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 23 ms 636 KB Correctly distinguished between possibility and impossibility
2 Correct 23 ms 760 KB Correctly distinguished between possibility and impossibility

Subtask #3
3.75 / 25.0

# Verdict Execution time Memory Grader output
1 Partially correct 6 ms 460 KB Valid reconstruction
2 Correct 23 ms 636 KB Correctly distinguished between possibility and impossibility
3 Correct 23 ms 760 KB Correctly distinguished between possibility and impossibility
4 Correct 30 ms 824 KB Correctly distinguished between possibility and impossibility
5 Correct 11 ms 592 KB Correctly distinguished between possibility and impossibility
6 Correct 10 ms 544 KB Correctly distinguished between possibility and impossibility

Subtask #4
2.25 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 23 ms 636 KB Correctly distinguished between possibility and impossibility
2 Correct 23 ms 760 KB Correctly distinguished between possibility and impossibility
3 Correct 504 ms 11824 KB Correctly distinguished between possibility and impossibility
4 Correct 496 ms 10688 KB Correctly distinguished between possibility and impossibility
5 Correct 511 ms 13984 KB Correctly distinguished between possibility and impossibility

Subtask #5
5.25 / 35.0

# Verdict Execution time Memory Grader output
1 Partially correct 6 ms 460 KB Valid reconstruction
2 Correct 23 ms 636 KB Correctly distinguished between possibility and impossibility
3 Correct 23 ms 760 KB Correctly distinguished between possibility and impossibility
4 Correct 30 ms 824 KB Correctly distinguished between possibility and impossibility
5 Correct 11 ms 592 KB Correctly distinguished between possibility and impossibility
6 Correct 10 ms 544 KB Correctly distinguished between possibility and impossibility
7 Correct 504 ms 11824 KB Correctly distinguished between possibility and impossibility
8 Correct 496 ms 10688 KB Correctly distinguished between possibility and impossibility
9 Correct 511 ms 13984 KB Correctly distinguished between possibility and impossibility
10 Correct 520 ms 11492 KB Correctly distinguished between possibility and impossibility
11 Correct 488 ms 9816 KB Correctly distinguished between possibility and impossibility
12 Correct 518 ms 11748 KB Correctly distinguished between possibility and impossibility
13 Correct 573 ms 14100 KB Correctly distinguished between possibility and impossibility
14 Correct 502 ms 11584 KB Correctly distinguished between possibility and impossibility