Day 13 added, bash & C.

day13/ex1.bash

@@ -0,0 +1,31 @@
+#!/bin/bash
+#
+# ex1.bash: Advent2020 game, day 13/game 1.
+
+CMD=${0##*/}
+shopt -s extglob
+
+declare -i num min=0 thebus curval curbus
+declare -a buses=()
+
+read -r num
+read -r line
+IFS=,
+for i in ${line}; do
+	if [[ $i != x ]]; then
+		buses+=("$i")
+		#echo B="${buses[@]}"
+	fi
+done
+for ((i=0; i<${#buses[@]}; ++i)); do
+	curbus=${buses[i]}
+	((curval=((num/curbus)+1)*curbus))
+	if ((min == 0 || curval < min)); then
+		min=curval
+		thebus=$curbus
+	fi
+done
+
+printf "%s : res=%d\n" "$CMD" $(((min-num)*thebus))
+
+exit 0