day 9, the hardest so far, spent to much time debugging

d09/part1.awk

@@ -0,0 +1,20 @@
+BEGIN{P["0_0"]=1; Hx=Hy=Tx=Ty=0}
+function abs(x) { return x>0?x:-x}
+{
+  print "==", Hx","Hy, ";", Tx","Ty, "==", $1, $2
+  for(i=1;i<=$2;i++){
+    if($1=="R") {Hx++}
+    if($1=="L") {Hx--}
+    if($1=="U") {Hy++}
+    if($1=="D") {Hy--}
+    dh = abs(Hx-Tx)  # tension horizontale
+    dv = abs(Hy-Ty)  # tension vertivale
+    if(dh>1 && $1=="R") {Tx++; if (dv>0) {Ty=Hy}}
+    if(dh>1 && $1=="L") {Tx--; if (dv>0) {Ty=Hy}}
+    if(dv>1 && $1=="U") {Ty++; if (dh>0) {Tx=Hx}}
+    if(dv>1 && $1=="D") {Ty--; if (dh>0) {Tx=Hx}}
+    P[Ty "_" Tx]=1
+    print Hx, Hy, ";", "dh:"dh, "dv:"dv, "=>", Tx, Ty
+  }
+}
+END{print length(P)}

d09/part2.py

@@ -0,0 +1,30 @@
+import sys
+
+rope = [(0,0) for _ in range(10)]
+P = [{(0,0)} for _ in range(10) ]
+D = {"R":(1,0),"L":(-1,0),"U":(0,1),"D":(0,-1)}
+
+for l in sys.stdin.read().splitlines():
+  M, q = l.split(" ")
+  q = int(q)
+  for k in range(q):
+    (x,y) = rope[0]
+    (dx,dy) = D[M]
+    rope[0] = (x+dx, y+dy)
+    for i in range(1,10):
+      (Hx,Hy) = rope[i-1]
+      (Tx,Ty) = rope[i]
+      dh = Hx-Tx  # tension horizontale
+      dv = Hy-Ty  # tension vertivale
+      if (abs(dh)>1):
+        Tx += 1 if dh > 0 else -1
+        if (abs(dv)>0):
+          Ty += 1 if dv > 0 else -1
+      elif (abs(dv)>1):
+        Ty += 1 if dv > 0 else -1
+        if (abs(dh)>0):
+          Tx += 1 if dh > 0 else -1
+      P[i].add((Tx,Ty))
+      rope[i] = (Tx,Ty)
+
+print(*(len(p) for p in P))