# UVa 514 - Rails

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# 題目大意
超級經典題

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# 題解
用stack模擬進出站

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#include <bits/stdc++.h>
#define ll long long
#define pb push_back
#define pf push_front
#define ft first
#define sec second
#define pr pair<int,int>
#define ISCC ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
using namespace std;
int t ,n ,m ,a[100005] ,A;
int main() 
{	
	ISCC;
	while(cin >> n && n)
	{
		while(cin >> a[1])
		{
			if(!a[1]){cout << '\n'; break;} 
			for(int i=2 ;i<=n ;i++) cin >> a[i];
			A = 1; stack<int> stk;
			for(int i=1 ;i<=n && A<=n ;i++)
			{
				stk.push(i);
				while(!stk.empty() && stk.top()==a[A]) A++ ,stk.pop();
			}
			if(stk.empty()) cout << "Yes\n";
			else cout << "No\n";
		} 
	}
	return 0;	
}