float x0=0; int g=0;
int tx=300,ty=40;
char Oi = char(183), Ou='+';

// MANAGE LABELS
Labels Lab = new Labels();  
class Labels {
  int m=0;
  int nI=16;
  int [] I =  new int [nI];
  int free=0;
  Labels() {for(int i=0;i<nI;i++) I[i]=i+1; I[nI-1]=-2;}
  void reset() {for(int i=0;i<nI;i++) I[i]=i+1; I[nI-1]=-2; free=0;m=0;}
  int grab() {int r=free; free=I[free]; I[r]=-1; if(free>m) m=free; return(r);}
  void release(int k) {I[k]=free; free=k;}
  void write() {for(int i=0;i<nI;i++) print(I[i]+","); println(" h="+free);}
  }
char name2(int i) {if (i<26) return char(i+65); else return char(i+71); }
char name(int i) {if (i<26) return char(i+97); else return char(i+39); }
// GATES
class gates { int p=0; int nG=64; gate [] G = new gate[nG]; gate t=new gate('t',height-r,d); gate f=new gate('f',height-r,d); 
  gates(int n) {nG=n; for(int i=0; i<nG; i++) G[i]=new gate(name(i),i*(r+s)+s/2,d,t,f);}
  void toggle() {for(int i=0; i<nG; i++) G[i].toggle();} 
  void reveal() {for(int i=0; i<nG; i++) G[i].reveal();} 
  boolean pickGate() { pt M = mouse(); for(int i=0; i<nG; i++) if (M.disTo(G[i].P)<s/2) { p=i; return(true); }; return(false); } 
  void flipGate() {G[p].V=!G[p].V;}
  void write() {print("gate["+p+"]="); G[p].write(); println();}
  void addGate() {G[nG]=new gate(name(nG),nG*(r+s)+s/2,d,t,f); nG++;}
  void addGate(char C) {G[nG]=new gate(C,nG*(r+s)+s/2,d,t,f); nG++;}
  void showConnections() {for(int i=0; i<nG; i++) G[i].showConnections(); }
  void drawWire() {G[0].drawLeftWire(); G[0].drawWire();}
  void drawWires() {G[0].drawLeftWire(); for(int i=0; i<nG-1; i++) G[i].drawWires();}
  void show() { stroke(cyan); for (int i=0; i<nL; i++) {line(21,d+5*dd+dd*i,height-19,d+5*dd+dd*i); 
       fill(dblue); text(i,height-15,d+5*dd+dd*i+4);   text(i,8,d+5*dd+dd*i+4); noFill();};
          stroke(green); new pt(height-12,d+5*dd+dd*outWire).show(7); for(int i=0; i<nG; i++) G[i].show(); }
  void showBlist() {
       fill(yellow); stroke(dred); strokeWeight(1); for(int i=0; i<nG; i++) G[i].showTri(); noFill();
       fill(black); for(int i=0; i<nG; i++) G[i].writeName(); noFill();
 //      for(int i=0; i<nG-1; i++) G[i].drawTT(G[i+1],2); 
//       for(int i=0; i<nG-1; i++) G[i].drawFF(G[i+1],0); 
//       for(int i=0; i<nG-1; i++) G[i].drawTI(G[i+1]); 
//       for(int i=0; i<nG-1; i++) G[i].drawFI(G[i+1]); 
      }
  void assignLabels() {
     Lab.reset();
     for (int i=0; i<nG; i++) G[i].i=-1; t.i=-1; f.i=-1;
     for (int i=0; i<nG; i++) G[i].assignLabels();
     G[0].i=0; outWire=t.i; // println("output is on wire "+t.i);
     }
  }
 
class gate { pt P = new pt (0,0); char N = '#'; boolean V=false;  gate T; gate F; int i=0, t=0, f=0; 
  gate(char c, float x, float y) {N=c; P.x=x; P.y=y;   }
  gate(char c, float x, float y, gate tG, gate fG) {N=c; P.x=x; P.y=y; T=tG; F=fG; }
  pt Pi() {pt Pi=new pt(P.x-r*0.7,bs-bss); return Pi;}
  pt Pt() {pt Pt=new pt(P.x+r*0.7,bs-bss-dd); return Pt;}
  pt Pf() {pt Pf=new pt(P.x+r*0.7,bs-bss+dd); return Pf;}
  void showTri() { beginShape(); Pi().v();Pt().v();Pf().v(); endShape(CLOSE); Pi().show(1); Pt().show(1); Pf().show(1); }
  void writeName() { Pi().showLabel(str(N),6,5);}
  void drawTI(gate G) { bezier(Pt().x,Pt().y,Pt().x+0.5*s,Pt().y, G.Pi().x-0.5*s,G.Pi().y,G.Pi().x,G.Pi().y ); }
  void drawFI(gate G) { bezier(Pf().x,Pf().y,Pf().x+0.5*s,Pf().y, G.Pi().x-0.5*s,G.Pi().y,G.Pi().x,G.Pi().y ); }
  void drawTT(gate G, int L) { bezier(Pt().x,Pt().y,Pt().x,Pt().y-dd*L, G.Pt().x,G.Pt().y-dd*L,G.Pt().x,G.Pt().y ); }
  void drawFF(gate G, int L) { bezier(Pf().x,Pf().y,Pf().x,Pf().y+dd*L, G.Pf().x,G.Pf().y+dd*L,G.Pf().x,G.Pf().y ); }
  void write() {if(!V) print("!"); print(N);}
  void assignLabels2() {
     if(i!=-1) {Lab.release(i); print(N+" released "+i+". "); };
     if(!V) {
        if(T.i==-1) {T.i=Lab.grab();  println(N+" grabbed "+t+" as t for "+T.N);}; t=T.i;
        if(F.i==-1) {F.i=Lab.grab();  println(N+" grabbed "+f+" as f for "+F.N);}; f=F.i;
        println();}
     else {
        if(F.i==-1) {F.i=Lab.grab();  println(N+" grabbed "+f+" as f for "+F.N);}; f=F.i;
        if(T.i==-1) {T.i=Lab.grab();  println(N+" grabbed "+t+" as t for "+T.N);}; t=T.i;
        println();}  
   }
  void assignLabels() { if(i!=-1) Lab.release(i); if(T.i==-1) T.i=Lab.grab(); t=T.i; if(F.i==-1) F.i=Lab.grab(); f=F.i; }
  void showConnections() {
  fill(magenta); noStroke(); P.makeTranslatedBy(-s/3,(5+i)*dd).show(3); P.makeTranslatedBy(0,(5+t)*dd).show(3); P.makeTranslatedBy(s/3,(5+f)*dd).show(3);
   }
  void show() {
   // piston pushing gate
    stroke(metal);  
    if (V) { P.showSegmentTo(P.makeTranslatedBy(0,2*dd+ss/2));  fill(green); P.makeTranslatedBy(0,2*dd+ss/2).show(4); noFill(); }
    else { P.showSegmentTo(P.makeTranslatedBy(0,2*dd)); fill(red); P.makeTranslatedBy(0,2*dd).show(4); noFill(); }
   // vertical wires
    stroke(orange); P.makeTranslatedBy(-s/3,dd+ss).showSegmentTo(P.makeTranslatedBy(-s/3,ss+(nL+3)*dd)); 
    stroke(green); P.makeTranslatedBy(0,dd+2*ss).showSegmentTo(P.makeTranslatedBy(0,ss+(nL+3)*dd)); 
    stroke(blue);P.makeTranslatedBy(s/3,dd+ss).showSegmentTo(P.makeTranslatedBy(s/3,ss+(nL+3)*dd));
   // swivel gate
    stroke(black); if(V) P.makeTranslatedBy(-s/3,dd+ss).showSegmentTo(P.makeTranslatedBy(0,dd+2*ss));
                   else P.makeTranslatedBy(-s/3,dd+ss).showSegmentTo(P.makeTranslatedBy(s/3,dd+ss));
   // destination circle above gate
    if(V) stroke(green); else stroke(red); fill(white); P.show(r); 
    if(V) {fill(dgreen); P.showChar(T.N);} else {fill(dred); P.showChar(F.N);};  noFill(); 
   // erase T-junction part after i-wire
    stroke(white); strokeWeight(4); P.makeTranslatedBy(-s/3+4,(5+i)*dd).showSegmentTo(P.makeTranslatedBy(-s/3+s/3-4,(5+i)*dd)); strokeWeight(2);
    }
  void showCurrent() {
    P.makeTranslatedBy(-s/3,dd+ss).showSegmentTo(P.makeTranslatedBy(-s/3,(5+i)*dd)); 
    if(V) P.makeTranslatedBy(-s/3,dd+ss).showSegmentTo(P.makeTranslatedBy(0,dd+2*ss));
    else P.makeTranslatedBy(-s/3,dd+ss).showSegmentTo(P.makeTranslatedBy(s/3,dd+ss));
    if (V) { P.makeTranslatedBy(0,dd+2*ss).showSegmentTo(P.makeTranslatedBy(0,(5+t)*dd));}
    else { P.makeTranslatedBy(s/3,dd+ss).showSegmentTo(P.makeTranslatedBy(s/3,(5+f)*dd));}
    }
 void reveal () {if (mouse().disTo(P)<s/2) {
    if(T==null) println("G_reveal: t=o"); else if(F==null) println("G_reveal: f=o"); else 
     text("="+N+i+"("+T.N+t+","+F.N+f+")",tx,ty+40); }; }
 void toggle () {if (mouse().disTo(P)<s/2) V=!V; }
 void drawWire() {
   if ((N!='t')&&(N!='f')) {this.showCurrent();
     if(V) {P.makeTranslatedBy(0,(5+t)*dd).showSegmentTo(T.P.makeTranslatedBy(-s/3,(5+T.i)*dd)); T.drawWire(); }
     else {P.makeTranslatedBy(s/3,(5+f)*dd).showSegmentTo(F.P.makeTranslatedBy(-s/3,(5+F.i)*dd)); F.drawWire(); };
     };
   }
 void drawWires() {
     P.makeTranslatedBy(0,(5+t)*dd).showSegmentTo(T.P.makeTranslatedBy(-s/3,(5+T.i)*dd)); 
     P.makeTranslatedBy(s/3,(5+f)*dd).showSegmentTo(F.P.makeTranslatedBy(-s/3,(5+F.i)*dd)); 
   }
 void drawLeftWire() {P.makeTranslatedBy(-s/3+4,(5+i)*dd).showSegmentTo(P.makeTranslatedBy(-s/3+4-10,(5+i)*dd)); }
  }
  
// NODES 
class nodes { int p=0; int nR=64;  node [] R = new node[nR];


 nodes(int n, gates Gs) {nR=n; for(int i=0; i<nR; i++) R[i]=new node(Gs.G[i],i*(r+s)+s/2,d-ds*s+s,Gs.t,Gs.f);}
 void show() { for(int i=0; i<nR; i++) R[i].show(); stroke(black); for(int i=0; i<nR; i++) R[i].P.show(r+1);  }
 boolean pickRoot() { pt M = mouse(); for(int i=0; i<nR; i++) if (M.disTo(R[i].P)<s/2) { p=i; return(true); } return(false); } 
 void flipOp() { for(int i=0; i<nR; i++) R[i].flipOp(); } 
 void depth() {depth=0; for(int i=0; i<nR; i++) if (depth<R[i].depth()) depth=R[i].depth(); } 
 void write() {print("root["+p+"]="); R[p].write(); println();}
 void writeRoots() { for(int i=0; i<nR; i++){ print("root["+i+"]=");  R[i].write();  println();}; }
 void writeString() {print("string["+p+"]="); S[0]=R[p].toString(); print(S[0]); println();}
 void writeStringNoP() {print("string["+p+"]="); String S=R[p].toStringNoP('x'); println(S);}
 void writeStringM() {String S=R[p].toStringM(false,R[p].O); println(S);}
 void snap() {x0=s; for(int i=0; i<nR; i++) {float y0=(vs-1)*R[i].depth(); R[i].snap(d-y0-vs-10); }; }
 void merge(char c) {if(p<nR-1) { node N=new node(R[p],c,R[p+1]); N.P.setTo(average(R[p].P,R[p+1].P)); R[p]=N; for (int i=p+1; i<nR-1; i++) R[i]=R[i+1]; nR--; };} 
 void split() {if (R[p].O!=' ') {nR++; for (int i=nR-2; i>p; i--) R[i+1]=R[i]; R[p+1]=R[p].R; R[p]=R[p].L;}; }
 void pivot() {for(int i=0; i<nR; i++) R[i].pivot(); }
 void reveal() {for(int i=0; i<nR; i++) R[i].reveal(); }
 void showBlist() {R[0].drawBlist(); }
 void showTF() {R[0].showTF(); }
 void setTF() {/* R[0].setTF(); */ R[0].lmg();}
 void passTF() {R[0].passTF(Gs.t,Gs.f); }
 void addNode() {R[nR]=new node(Gs.G[Gs.nG-1],nR*(r+s)+s/2,d,Gs.t,Gs.f); nR++;}
 }

class node { pt P = new pt (0,0);  node L; char O = ' ';  node R;  gate G; gate T; gate F; int f, t, c;
   gate SG; gate EG;   // starting and ending gates 
   gate TG; gate FG; // gates to branch arriving top abd bottom Blist wires
   int t1=0, t2=0, f1=0, f2=0;   // numbers top/bottom of wires before and after these gates
   int c1=0, c2=0, c3=0;   // 3 costs
   boolean tt=true;
  node() { }
  node(node pL, char c, node pR) {L=pL; O=c; R=pR; G=Gs.G[0]; T=Gs.t; F=Gs.f;};
  node(gate pG, float x, float y, gate tG, gate fG) {G=pG; P.x=x; P.y=y; T=tG; F=fG;}
  void write () {if(O==' ') print(G.N); else { print("("); L.write();  print(O); R.write(); print(")");}; }
  void reveal () {
    if (mouse().disTo(P)<s/2) {
      if(T==null) println("N_reveal: t=@"); 
      else if(F==null) println("N_reveal: f=@"); 
           else { if(O==' ') text(">"+G.N,tx,ty); 
                  else text(O+"("+T.N+","+F.N+"): tt="+tt+", c1="+c1+", c2="+c2+", c3="+c3+", c="+max(c1,c2,c3),tx,ty); 
                };
      }
    else if(O!=' ') {L.reveal(); R.reveal();};  
    };
  int depth() {int d=0; if (O!=' ') d=1+max(L.depth(),R.depth()); return(d);}
  void pivot() {if(O!=' ') {if (mouse().disTo(P)<s/2) {node N; N=L; L=R; R=N; } else {L.pivot(); R.pivot();}; }; }
  void flipOp() {if (mouse().disTo(P)<s/2) {if(O==' ') G.V=!G.V; else { if (O==Ou) O=Oi; else O=Ou; }; compile();}    // O=char(183);
                 else if(O!=' ') {L.flipOp(); R.flipOp();} ;  }
  float snap (float y0) {float x=x0;
    if (O==' ') { P.setTo(x0,y0); G.P.setTo(x0,d); x0+=s;}
    else { x = ( L.snap(y0+vs) + R.snap(y0+vs) )/2; P.setTo(x,y0); };
    return(x);
    }
  void showTF() {if(O==' ') {stroke(green,60); P.showSegmentTo(G.T.P); stroke(red,60); P.showSegmentTo(G.F.P); }
    else {//stroke(green,60); P.showSegmentTo(T.P); stroke(red,60); P.showSegmentTo(F.P); 
     L.showTF(); R.showTF(); };}
  void show() {if (O==' ') {stroke(orange); if(showDrops) P.showSegmentTo(G.P); 
      if (showLeaves) {stroke(orange); fill(white); P.show(r); 
      fill(dblue); P.showChar(G.N); noFill(); }; }
    else {stroke(metal); P.showSegmentTo(L.P); P.showSegmentTo(R.P); 
   fill(white); P.show(r); fill(dgreen); noStroke();
    if(O==Oi)  P.show(r/3); else stroke(dgreen); strokeWeight(3); P.showCross(r/2); strokeWeight(2);
   noFill(); L.show(); R. show(); }; }
  String toString() {String S=""; if(O==' ') S+=G.N; else S+=O+L.toString()+R.toString(); return(S);}
  String toStringP() {String S=""; if(O==' ') S+=G.N; else S+="("+L.toStringP()+O+R.toStringP()+")"; return(S);}
  String toStringNoP(char pop) {String S=""; String op=""; if(O==Ou) op+=Ou;
     if(O==' ') S+=G.N; else 
      { if((O!=pop)&&(pop==Oi)) S+="("+L.toStringNoP(O)+op+R.toStringNoP(O)+")"; else S+=L.toStringNoP(O)+op+R.toStringNoP(O);  };
      return(S);}
  String toStringM(boolean right, char pop) {String S=""; String op=""; if(O==Ou) op+=Ou;
     if(O==' ') S+=G.N; else  
      { S+=L.toStringM(false,O)+op+R.toStringM(true,O); if ((right&&((pop!=Ou)||(O!=Oi)))||((pop==Oi)&&(O==Ou)&&!right)) S="("+S+")";  };
      return(S);}
  void setTF() {this.lmg(); }
  gate lmg() {gate LMG; if(O==' ') LMG=G; else {if(O==Ou) F=R.lmg(); else T=R.lmg(); LMG=L.lmg(); }; return(LMG);}
  void rm(boolean opIsX) {if(O==' ') G.V=!opIsX; else {if(O==Ou) {L.rm(false); R.rm(opIsX); } else {L.rm(true); R.rm(opIsX); };};}
  void passTF(gate pT, gate pF) {
    if(O==' ')  {G.T=pT; G.F=pF; T=pT; F=pF;};
    if(O==Ou)  {L.passTF(pT,F); R.passTF(pT,pF); };
    if(O==Oi)  {L.passTF(T,pF); R.passTF(pT,pF); };
     }
  int pH() {if(O==' ') return(0); int cL=L.pH(); int cR=R.pH(); if(cR>cL) {node N; N=L; L=R; R=N; }; return(1+max(cL,cR)); }
  void pO() {if(O==' ') {c1=0; c2=0; c3=0; tt=true;} else {L.pO(); R.pO(); if (flipCost()<flipCost()) flipCost(); }; }  
  float flipCost() {
         node NN; NN=L; L=R; R=NN;
         if((O==Oi)&&L.tt&&R.tt)   { tt=true;  c1=L.c1; c2=max(max(L.c2,L.c3,2),max(R.c1+1,R.c2)); c3=R.c3;};
         if((O==Oi)&&L.tt&&!R.tt)  { tt=true;  c1=L.c1; c2=max(max(L.c2,L.c3,2),R.c1+1); c3=max(R.c2+1,R.c3);};
         if((O==Oi)&&!L.tt&&R.tt)  { tt=true;  c1=max(L.c1,L.c2); c2=max(max(L.c3,2),max(R.c1+1,R.c2)); c3=R.c3;};
         if((O==Oi)&&!L.tt&&!R.tt) { tt=true;  c1=max(L.c1,L.c2); c2=max(max(L.c3,2),R.c1+1); c3=max(R.c2+1,R.c3);};
         if((O==Ou)&&L.tt&&R.tt)   { tt=false; c1=max(L.c1,L.c2); c2=max(max(L.c3,2),R.c1+1); c3=max(R.c2+1,R.c3);};
         if((O==Ou)&&L.tt&&!R.tt)  { tt=false; c1=max(L.c1,L.c2); c2=max(max(L.c3,2),max(R.c1+1,R.c2)); c3=R.c3;};
         if((O==Ou)&&!L.tt&&R.tt)  { tt=false; c1=L.c1; c2=max(max(L.c2,L.c3,2),R.c1+1); c3=max(R.c2+1,R.c3);};
         if((O==Ou)&&!L.tt&&!R.tt) { tt=false; c1=L.c1; c2=max(max(L.c2,L.c3,2),max(R.c1+1,R.c2)); c3=R.c3;};
        return  max(c1,c2,c3);
     }   
  void pOsaved3() { 
     if(O==' ') {t1=0; t2=0; f1=0; f2=0;} else {L.pO(); R.pO();};
     if(O==Oi) {if(R.f1>L.f1) {node N; N=L; L=R; R=N; }; t1=max(L.t1,L.t2,R.t1); t2=R.t2; f1=L.f1; f2=max(L.f2,R.f1+1,R.f2);};
     if(O==Ou) {if(R.t1>L.t1) {node N; N=L; L=R; R=N; }; f1=max(L.f1,L.f2,R.f1); f2=R.f2; t1=L.t1; t2=max(L.t2,R.t1+1,R.t2); };
     }  
  void pOsaved2() { 
     if(O==' ') {f=0; t=0; c=0;} else {L.pO(); R.pO();};
     if(O==Oi) {if(R.t>L.t) {node N; N=L; L=R; R=N; }; t=L.t; f=max(L.c,R.f); c=max(L.c,R.c,R.f+1);};
     if(O==Ou) {if(R.f>L.f) {node N; N=L; L=R; R=N; }; f=L.f; t=max(L.c,R.t); c=max(L.c,R.c,R.t+1);};
     }  
  void pOsaved() { 
     if(O==' ') {f=0; t=0;} else {L.pO(); R.pO();};
     if(O==Oi) {if(R.f>L.f) {node N; N=L; L=R; R=N; }; t=max(1+L.t,R.t); f=max(L.f,R.f); };
     if(O==Ou) {if(R.t>L.t) {node N; N=L; L=R; R=N; }; f=max(1+L.f,R.f); t=max(L.t,R.t); };
     }  
  void drawBlist() { 
    if(O==' ') { SG=G; EG=G; TG=G; FG=G; t1=0; t2=0; f1=0; f2=0;} 
    else {
      L.drawBlist(); R.drawBlist();
      if(O==Oi) {SG=L.SG; EG=R.EG; FG=L.FG; TG=R.TG; t1=max(L.t1,L.t2,R.t1); t2=R.t2; f1=L.f1; f2=max(L.f2,R.f1+1,R.f2); L.EG.drawTI(R.SG); L.EG.drawFF(R.FG,R.f1+1);};
      if(O==Ou) {SG=L.SG; EG=R.EG; FG=R.FG; TG=L.TG; f1=max(L.f1,L.f2,R.f1); f2=R.f2; t1=L.t1; t2=max(L.t2,R.t1+1,R.t2);L.EG.drawFI(R.SG); L.EG.drawTT(R.TG,R.t1+1);};
      };
    }
  }  // end node

// ARCHIVAL
void fromString() {if (S[0].length()==0) return; println("parsing ");  println("<"+S[0]+"> "+S[0].length()+" chars");
  ng=0; Gs.nG=0; Ns.nR=0;  g=0;
  Ns.nR++; node N=make();  println();  println("done");
  Ns.R[0]= N;  ng=Gs.nG; Buttons.B[0].V=ng; resize();
  }

void fromStringR() {if (S[0].length()==0) return; println("parsingR ");  println("<"+S[0]+"> "+S[0].length()+" chars");
  ng=0; Gs.nG=0; Ns.nR=0;  g=0;
  Ns.nR++; node N=makeR();   println();  println("done");
  Ns.R[0]= N;  ng=Gs.nG; Buttons.B[0].V=ng; resize();
  }

node make() {
    node N = new node();  N.T=Gs.t; N.F=Gs.f;
    char C=S[0].charAt(0); if(C=='+') C=Ou; if(C=='x') C=Oi; if(C=='.') C=Oi;  S[0]=S[0].substring(1); 
    if((C!=Ou)&&(C!=Oi)) {Gs.addGate(name(g++)); N.G=Gs.G[Gs.nG-1]; N.O=' ';}
    else {N.O=C; N.L=make(); N.R=make(); }
    return(N); }

node makeR() {
    node N = new node();  N.T=Gs.t; N.F=Gs.f;
    if(S[0].length()==0) {println(); println("Rempty"); return(N);} else {
    char C=S[0].charAt(0); if(C=='+') C=Ou; if(C=='.') C=Oi; S[0]=S[0].substring(1); print(C); 
    if((C!=Ou)&&(C!=Oi)) {Gs.addGate(C); N.G=Gs.G[Gs.nG-1]; N.O=' ';}
    else {N.O=C; N.L=makeR(); N.R=makeR(); }
    return(N); }
    }