Day 21

21/01.sh

@@ -0,0 +1,32 @@
+#!/bin/bash
+
+positions=()
+scores=()
+
+while read line; do
+  positions+=( $(sed 's/^.* \([0-9]*\)$/\1/' <<< $line) )
+  scores+=( 0 )
+done
+
+dice_next_value=1
+player_index=0
+finished=0
+n_rolls=0
+
+while [ $finished -eq 0 ]; do
+  roll=$((dice_next_value+dice_next_value+1+(dice_next_value+1)%100+1))
+  dice_next_value=$(((dice_next_value+2)%100+1))
+  positions[$player_index]=$(((positions[player_index]+roll-1)%10+1))
+  scores[$player_index]=$((scores[player_index]+positions[player_index]))
+  if [ ${scores[$player_index]} -ge 1000 ]; then
+    finished=1
+  fi
+  player_index=$(((player_index+1)%${#positions[@]}))
+  n_rolls=$((n_rolls+3))
+done
+
+for score in ${scores[@]}; do
+  if [ $score -lt 1000 ]; then
+    echo $((score*n_rolls))
+  fi
+done