Submission #315101

#	Time	Username	Problem	Language	Result	Execution time	Memory
315101		Seanliu	Cat (info1cup19_cat)	C++14	Compilation error	0 ms	0 KiB

cat

#include <iostream>
#include <vector>
#include <utility>
#define pii pair<int,int>
#define F first
#define S second
#define ericxiao ios_base::sync_with_stdio(0);cin.tie(0);
#define endl '\n'
using namespace std;

const int maxN = 3e6 + 326;

int N, arr[maxN], pos[maxN], T, posc, ansc;
pii ans[maxN];
bool vis[maxN];

inline void makeMove(int i, int j){
	swap(arr[i], arr[j]);
	swap(arr[N - i + 1], arr[N - j + 1]);
}

inline void disp(){
	for(int i = 1; i <= N; i++) cout << arr[i] << " \n"[i == N];
}

inline void solve(){
	cin >> N;
	for(int i = 1; i <= N; i++) cin >> arr[i];
	for(int i = 1; i <= N / 2; i++) if(arr[i] + arr[N - i + 1] != N + 1){
		cout << -1 << endl;
		return;
	}
	posc = ansc = 0;
	for(int i = 1; i <= N / 2; i++) if(arr[i] > arr[N - i + 1]) pos[posc++] = i;
	if(posc & 1){ //not sure about this
		cout << -1 << endl;
		return;
	}
	/*
	cout << "have: ";
	for(int x : pos) cout << x << " ";
	cout << endl;
	*/
	for(int i = 0; i < (int)pos.size(); i += 2){
		makeMove(pos[i], N - pos[i + 1] + 1);	
		ans[ansc++] = {pos[i], N - pos[i + 1] + 1};
	}
	//disp();
	fill(vis, vis + N + 1, false);
	for(int i = 1; i <= N / 2; i++){
		while(i != arr[i]){
			int nxt = arr[i];
			makeMove(i, arr[i]);
			ans[ansc++] = {i, nxt};
			//disp();
		}
	}
	cout << ansc << " " << ansc << endl;
	for(int i = 0; i < ansc; i++) cout << ans[i].F << " " << ans[i].S << endl;
}

int main(){
	//ericxiao
	cin >> T;
	while(T--){
		solve();
	}
}

Compilation message (stderr)

cat.cpp: In function 'void solve()':
cat.cpp:44:30: error: request for member 'size' in 'pos', which is of non-class type 'int [3000326]'
   44 |  for(int i = 0; i < (int)pos.size(); i += 2){
      |                              ^~~~