/*************************************************************************
 *  Compilation:  javac Circuit.java
 *
 *  ADT for circuit with M inputs and N outputs.
 *
 *************************************************************************/

public abstract class Circuit {
    private Wire[] in;     // input wires
    private Wire[] out;    // output wires

    // construct a new circuit with M input wires and N output wires
    public Circuit(int M, int N) {
        in  = new Wire[M];
        out = new Wire[N];
        for (int i = 0; i < M; i++) in[i]  = new Wire(this);
        for (int j = 0; j < N; j++) out[j] = new Wire(this);
    }

    protected Wire  inAt(int i) { return in[i];  }   // return the ith input wire
    protected Wire outAt(int j) { return out[j]; }   // return the jth output wire

    public void propagate() { }

}