X-Git-Url: https://git.sommitrealweird.co.uk/advent-of-code-2019.git/blobdiff_plain/c4d07ccc686ba834151431d1fbd3cf35fe2f3b06..3ca1513febb0049d737bb0f3bd23f38e81e3485f:/day3/wires.sh

diff --git a/day3/wires.sh b/day3/wires.sh
index a28765a..b94ef0b 100644
--- a/day3/wires.sh
+++ b/day3/wires.sh
@@ -12,61 +12,19 @@ set -e
 #wire_2=(U62 R66 U55 R34 D71 R55 D58 R83)
 
 # these wires should get 135
-wire_1=(R98 U47 R26 D63 R33 U87 L62 D20 R33 U53 R51)
-wire_2=(U98 R91 D20 R16 D67 R40 U7 R15 U6 R7)
+#wire_1=(R98 U47 R26 D63 R33 U87 L62 D20 R33 U53 R51)
+#wire_2=(U98 R91 D20 R16 D67 R40 U7 R15 U6 R7)
 
 # read in data from file instead
-#exec 3<input.txt
-#IFS="," read -u 3 -a wire_1
-#IFS="," read -u 3 -a wire_2
-
-get_min_max() {
-    local -n wire=$1
-    horz_min=0
-    horz_max=0
-    vert_min=0
-    vert_max=0
-    cur_horz=0
-    cur_vert=0
-    for instruction in "${wire[@]}"; do
-        direction=${instruction:0:1}
-        amount=${instruction:1}
-        case $direction in
-            U)
-                cur_vert=$((cur_vert+$amount))
-                if [ $cur_vert -gt $vert_max ]; then
-                    vert_max=$cur_vert
-                fi
-                ;;
-            D)
-                cur_vert=$((cur_vert-$amount))
-                if [ $cur_vert -lt $vert_min ]; then
-                    vert_min=$cur_vert
-                fi
-                ;;
-            R)
-                cur_horz=$((cur_horz+$amount))
-                if [ $cur_horz -gt $horz_max ]; then
-                    horz_max=$cur_horz
-                fi
-                ;;
-            L)
-                cur_horz=$((cur_horz-$amount))
-                if [ $cur_horz -lt $horz_min ]; then
-                    horz_min=$cur_horz
-                fi
-                ;;
-        esac
-    done
-
-    echo "$horz_min,$horz_max,$vert_min,$vert_max"
-}
+exec 3<input.txt
+IFS="," read -u 3 -a wire_1
+IFS="," read -u 3 -a wire_2
 
 trace_wire() {
     local -n w=$1
     local -n b=$2
     local -n c=$3
-    min_left=$4
+    wire_number=$4
     cur_vert=0
     cur_horz=0
     moved=0
@@ -92,131 +50,41 @@ trace_wire() {
 
         case $direction in
             U|D)
-                last_replace_char="|"
-                offset=$((0-$min_left))
-                offset=$((offset+$cur_horz))
                 for (( moved=1; moved <= $amount; moved++ )); do
                     cur_vert=$((cur_vert${operator}1))
-                    cur_line=${b[$cur_vert]}
-                    cur_char=${cur_line:$offset:1}
-                    replace_char="|"
-                    if [ $cur_char = "-" ] || [ $cur_char = "|" ]; then
-                        replace_char="X"
-                        c+=($cur_horz,$cur_vert)
-                    fi
-                    if [ $moved -eq $amount ]; then
-                        replace_char="+"
+                    if [ ${b[$cur_horz,$cur_vert]+a} ] && [ $wire_number -eq 2 ]; then
+                        if [ ${b[$cur_horz,$cur_vert]} -eq 1 ]; then
+                            c+=($cur_horz,$cur_vert)
+                            b[$cur_horz,$cur_vert]=3
+                        fi
+                        continue
                     fi
-                    if [ $cur_vert -eq 0 ] && [ $cur_horz -eq 0 ]; then
-                        replace_char='o'
-                    fi
-                    new_line="${cur_line:0:$((offset))}${replace_char}${cur_line:$((offset+1))}"
-                    b[$cur_vert]=$new_line
+                    b[$cur_horz,$cur_vert]=$wire_number
                 done
                 ;;
             L|R)
-                last_replace_char="-"
-                # this could change multiple characters in the line
                 for (( moved=1; moved <= $amount; moved++ )); do
                     cur_horz=$((cur_horz${operator}1))
-                    offset=$((0-$min_left))
-                    offset=$((offset+$cur_horz))
-                    cur_line=${b[$cur_vert]}
-                    cur_char=${cur_line:$offset:1}
-                    replace_char="-"
-                    if [ $cur_char = "-" ] || [ $cur_char = "|" ]; then
-                        replace_char="X"
-                        c+=($cur_horz,$cur_vert)
-                    fi
-                    if [ $moved -eq $amount ]; then
-                        replace_char="+"
-                    fi
-                    if [ $cur_vert -eq 0 ] && [ $cur_horz -eq 0 ]; then
-                        replace_char='o'
+                    if [ ${b[$cur_horz,$cur_vert]+a} ] && [ $wire_number -eq 2 ]; then
+                        if [ ${b[$cur_horz,$cur_vert]} -eq 1 ]; then
+                            c+=($cur_horz,$cur_vert)
+                            b[$cur_horz,$cur_vert]=3
+                        fi
+                        continue
                     fi
-                    new_line="${cur_line:0:$((offset))}${replace_char}${cur_line:$((offset+1))}"
-                    b[$cur_vert]=$new_line
+                    b[$cur_horz,$cur_vert]=$wire_number
                 done
                 ;;
         esac
     done
-
-    cur_line=${b[$cur_vert]}
-    offset=$((0-$min_left))
-    offset=$((offset+$cur_horz))
-    if [ ${cur_line:$offset:1} != 'X' ]; then
-        new_line="${cur_line:0:$((offset))}${last_replace_char}${cur_line:$((offset+1))}"
-        b[$cur_vert]=$new_line
-    fi
-    echo
 }
 
-make_board() {
-    local -n mm=$1
-    local -n b=$2
-
-    min_horz=${mm[0]}
-    if [ $min_horz -gt 0 ]; then
-        min_horz=0
-    fi
-
-    min_vert=${mm[2]}
-    if [ $min_vert -gt 0 ]; then
-        min_vert=0
-    fi
-
-    max_horz=${mm[1]}
-    total_horz=$(($max_horz - $min_horz))
-
-    max_vert=${mm[3]}
-
-    cur_vert=${min_vert}
-    blank_string=$(printf ".%.0s" $(eval echo '{0..'$total_horz'}'))
-    while [[ $cur_vert -le ${max_vert} ]]; do
-        if [[ $cur_vert -eq 0 ]]; then
-            offset=$((0-${mm[0]}))
-            line="${blank_string:0:$offset}o${blank_string:$((offset+1))}"
-            b[$cur_vert]=$line
-        else
-            b[$cur_vert]=$blank_string
-        fi
-        cur_vert=$((cur_vert+1))
-    done
-}
-
-echo "Getting board boundaries"
-IFS="," read -a min_max < <(get_min_max wire_1)
-IFS="," read -a min_max_2 < <(get_min_max wire_2)
-
-# do the minimums first
-for pos in 0 2; do
-    if [ ${min_max[$pos]} -gt ${min_max_2[$pos]} ]; then
-        min_max[$pos]=${min_max_2[$pos]}
-    fi
-done
-
-# now the maximums
-for pos in 1 3; do
-    if [ ${min_max[$pos]} -lt ${min_max_2[$pos]} ]; then
-        min_max[$pos]=${min_max_2[$pos]}
-    fi
-done
-
-echo "  ${min_max[@]}"
-
-# we now know exactly how big the grid is, which is handy, as we'll use it to do offsets
 declare -A board
 declare -a cross_wires
-echo "Building board"
-make_board min_max board
 echo "Tracing first wire"
-trace_wire wire_1 board cross_wires ${min_max[0]}
+trace_wire wire_1 board cross_wires 1
 echo "Tracing second wire"
-trace_wire wire_2 board cross_wires ${min_max[0]}
-
-for (( a=${min_max[3]}; a>=${min_max[2]}; a-- )); do
-    echo ${board[$a]}
-done
+trace_wire wire_2 board cross_wires 2
 
 echo "Wires cross at:"
 min_distance=-1