Solve the no connection puzzle: Difference between revisions

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=={{header|Chapel}}==

<lang chapel>type hole = int;

param A : hole = 1;

param B : hole = A+1;

param C : hole = B+1;

param D : hole = C+1;

param E : hole = D+1;

param F : hole = E+1;

param G : hole = F+1;

param H : hole = G+1;

param starting : int = 0;

const holes : domain(hole) = { A,B,C,D,E,F,G,H };

const graph : [holes] domain(hole) = [ A => { C,D,E },

B => { D,E,F },

C => { A,D,G },

D => { A,B,C,E,G,H },

E => { A,B,D,F,G,H },

F => { B,E,H },

G => { C,D,E },

H => { D,E,F }

];

proc check( configuration : [] int, idx : hole ) : bool {

var good = true;

for adj in graph[idx] {

if adj >= idx then continue;

if abs( configuration[idx] - configuration[adj] ) <= 1 {

good = false;

break;

}

}

return good;

}

proc solve( configuration : [] int, pegs : domain(int), idx : hole = A ) : bool {

for value in pegs {

configuration[idx] = value;

if check( configuration, idx ) {

if idx < holes.size {

var prePegs = pegs;

if solve( configuration, prePegs - value, idx + 1 ){

return true;

}

} else {

return true;

}

}

}

configuration[idx] = starting;

return false;

}

proc printBoard( configuration : [] int ){

return

"\n " + configuration[A] + " " + configuration[B]+ "\n" +

" /|\\ /|\\ \n"+

" / | X | \\ \n"+

" / |/ \\| \\ \n"+

" " + configuration[C] +" - " + configuration[D] + " - " + configuration[E] + " - " + configuration[F] + " \n"+

" \\ |\\ /| / \n"+

" \\ | X | / \n"+

" \\|/ \\|/ \n"+

" " + configuration[G] + " " + configuration[H]+ "\n";

}

proc main(){

var configuration : [holes] int;

for idx in holes do configuration[idx] = starting;

var pegs : domain(int) = {1,2,3,4,5,6,7,8};

solve( configuration, pegs );

writeln( printBoard( configuration ) );

}

</lang>

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