Fix minor bugs based on different input files

einarjon · einarjon · commit 7c51b9dd1630 · 2024-03-07T15:05:10.000Z
1: Negative numbers + grep are bad Will make grep wait forever for input from stdin 2: Arithmetic context for characters is bad When $x=='x' or $b=='b' we have an infinite recursion problem. https://stackoverflow.com/questions/30404863/expression-recursion-level-exceeded 3: Wrong index used. 9: Off-by-one error. 11: Failed variable rename in shellcheck cleanup. Skip call to sort.
diff --git a/01.sh b/01.sh
@@ -1,7 +1,7 @@
 #! /usr/bin/env bash
 input=${1:-1.txt}
 A=($(sort -n "$input"));
-for a in "${A[@]}"; do grep -wq $((2020-a)) "$input" && break; done
+for a in "${A[@]}"; do grep -q -- ^$((2020-a))$ "$input" && break; done
 echo "1A: $((2020-a)) + $a = $(((2020-a)*a))"
-b=:; for a in "${A[@]}";do for i in "${A[@]}"; do grep -wq $((2020-a-i)) "$input" && b=break; $b ; done; $b; done
+b=:; for a in "${A[@]}";do for i in "${A[@]}"; do grep -q -- ^$((2020-a-i))$ "$input" && b=break; $b; done; $b; done
 echo "1B: $((2020-a-i)) + $a + $i = $(((2020-a-i)*a*i))"
diff --git a/02.sh b/02.sh
@@ -4,5 +4,5 @@ IFS=$'-:\ \n'
 while read -r m M b c; do x=${c//[^$b]}; (( ${#x} >= m && ${#x} <= M && ++ans)); done < "${1:-2.txt}"
 echo "2A: $ans"
 ans=0
-while read -r m M b c; do x=${c:m-1:1}; y=${c:M-1:1}; (( x != y && ( b == x || b == y ) && ++ans)); done < "${1:-2.txt}"
+while read m M b c; do x=${c:m-1:1}; y=${c:M-1:1}; [[ $x != $y ]] && [[ $b == $x || $b == $y ]] && ((++ans)); done < ${1:-2.txt}
 echo "2B: $ans"
diff --git a/03.sh b/03.sh
@@ -4,5 +4,5 @@ for i in "${A[@]}"; do x+=${i:k:1}; ((k=(k+j)%l)); done; x=${x//\.}
 echo "3A: ${#x}"
 idx2=$(seq 0 2 $((${#A[@]}-1)))
 for j in 1 3 5 7; do x=""; k=0; for i in "${A[@]}"; do x+=${i:k:1}; ((k=(k+j)%l)); done; x=${x//\.}; total+="*${#x}"; done
-x=""; k=0; for i in $idx2; do x+=${A[i]:k:1}; ((k=(k+j)%l)); done ; x=${x//\.}; total+="*${#x}"
+x=""; k=0; for i in $idx2; do x+=${A[i]:k:1}; ((k=(k+2)%l)); done ; x=${x//\.}; total+="*${#x}"
 echo "3B: ${total:2} = $((total))"
diff --git a/09.sh b/09.sh
@@ -20,5 +20,5 @@ while [ "$sum" != "${A[i]}" ]; do
     fi
     [[ $j -ge $i ]] && echo NOT FOUND && break
 done
-B=($(printf "%s\n" "${A[*]:k:j-k+1}" | sort -n))
+B=($(printf "%s\n" "${A[*]:k:j-k}" | sort -n))
 echo "9B: $k..$j = $((B[0]+B[-1]))"
diff --git a/11.sh b/11.sh
@@ -2,7 +2,7 @@
 A=($(tr "L" "X" < "${1:-11.txt}"))
 B=(.${A//?/.}.); for i in "${A[@]}"; do B+=(.$i.); done; B+=($B); C=("${B[@]}");
 J=$(seq 1 ${#A}); I=$(seq 1 ${#A[@]}); CHANGE=($I); round=0
-while [ ${#change} != 0 ]; do
+while [ ${#I} != 0 ]; do
     CHANGE=(); l=
     for i in $I; do
         for j in $J; do
@@ -14,13 +14,13 @@ while [ ${#change} != 0 ]; do
             fi
             l+=$x
         done
-        [ "${B[i]}" != .$l. ] && CHANGE+=($((i-1)) $i $((i+1)))
+        [ "${B[i]}" != .$l. ] && CHANGE[i-1]=1 && CHANGE[i]=1 && CHANGE[i+1]=1
         C[i]=.$l.; l=
     done
     B=("${C[@]}")
-    I=$(printf "%s\n" "${CHANGE[@]}" |sort -u)
+    I=${!CHANGE[@]}
     ((++round==1)) && B=("${C[@]//X/x}")
-    #((round%10)) || echo "$round: $((${#change[@]}/3))"
+    #((round%10)) || echo "$round: ${#CHANGE[@]}"
 done
 ans="${B[*]}"; ans=${ans//[ L.]}
 echo "11A: ${#ans}"
