Educational Codeforces Round 99 (Rated for Div. 2) D. Sequence and Swaps

链接：Problem - D - Codeforces

思路：给定的x从第一个开始交换 遇到第一个比它自己x大的数就交换 因为如果当前不换的话 后面的每一个进行交换之后都不会形成递增了 又因为数据范围是500 每次交换都可以检查一下是否程递增 如果是 则输出当前换的个数 如果跑完还没有符合 那就输出-1

#include<bits/stdc++.h>
#define ios ios::sync_with_stdio(0),cin.tie(0),cout.tie(0)
using namespace std;using ll = long long;using PLL = pair<ll,ll>;
const ll MAX = 1e18;const ll MIN = -1e18;const ll INF=0x3f3f3f3f;
const ll Q = 2e5+9;const ll MOD = 1e9 + 7;
ll a[Q];ll n,x;
bool check(){
	for (ll i = 1; i < n; i++)
	{
		if(a[i+1]<a[i]){
			return false;
		}
	}
	return true;
}
void solve(){
   cin>>n>>x;
   for (ll i = 1; i <= n; i++)
	cin>>a[i];
	ll now=0;
	for (ll i = 1; i <= n; i++)
	{
		if(check()){
			cout<<now<<"\n";
			return;
		}
		if(x<a[i]) swap(a[i],x),now++;
	}
	
	cout<<-1<<"\n";

   
}
int main(){
	ios;ll _=1;cin>>_;
	while (_--)solve();
	return 0;
}