perle

#include <fstream>
#include <vector>
#include <stack>

using namespace std;

ifstream fin(“perle.in”);
ofstream fout (“perle.out”);
int n;
vector <int> v;

bool Perla( char c)
{ stack<char> stk; int p = 1; char l; stk.push( c );

while( p <= n ) { if( stk.empty()) return false; l = stk.top(); stk.pop(); if( l 'B') { if( v[p] 2) { stk.push(‘B’); p++; continue; } if( p + 4 <= n && v[p] 1 && v[p + 2] 3) { stk.push(‘C’); p = p + 4; continue; } if( v[p] 3 ) return false; } if( l ‘C’) {//C -> 2 | 3BC | 12A if( v[p] 2 ) { p++; continue; } if( v[p] 3 ) { stk.push(‘C’); stk.push(‘B’); p++; continue; } if(p + 2 <= n && v[p] 1 && v[p + 1] 2 ) { p = p + 3; continue; } } } return stk.empty(); } int main() { int m; fin >> m; for(int i = 1; i <= m; i++) { fin >> n; v = vector<int>( n + 1); for(int j = 1; j <= n; j++) fin >> v[j]; if( Perla(‘B’) true || Perla ('C') true || n == 1) fout << “1\n”; else fout << “0\n”; }

}