习题8-20(uva-1620)

#include <iostream>
#include <istream>
#include <sstream>
#include <vector>
#include <stack>
#include <list>
#include <map>
#include <set>
#include <deque>
#include <queue>
#include <cstring>
#include <unordered_map>
#include <unordered_set>
#include <algorithm>
#include <numeric>
#include <chrono>
#include <ctime>
#include <cmath>
#include <cctype>
#include <string>
#include <cstdio>
#include <iomanip>


#include <thread>
#include <mutex>
#include <condition_variable>
#include <functional>
#include <iterator>
using namespace std;
const int maxn = 507;
int input[maxn],n;
int main()
{
    
    
	int t;
	cin >> t;
	while (t--) {
    
    
		cin >> n;
		int* first = input,cnt = 0;
		for (int i = 0; i < n; i++) cin >> *first++;

		for (int i = 0; i < n; i++) {
    
    
			for (int j = i + 1; j < n; j++) {
    
    
				if (input[i] > input[j])++cnt;
			}
		}
		if ((cnt & 1) && (n & 1)) cout << "impossible" << endl;
		else cout << "possible" << endl;
	}
	return 0;
}