Move to have day be 2 digit always
[advent-of-code-2020.git] / day03 / count_trees.sh
diff --git a/day03/count_trees.sh b/day03/count_trees.sh
new file mode 100644 (file)
index 0000000..53925a3
--- /dev/null
@@ -0,0 +1,51 @@
+#!/bin/bash
+
+start_letter=0
+line_number=0
+tree_count=0
+
+for line in $(<input.txt); do
+    line_number=$((line_number+1))
+    if [ $line_number -eq 1 ]; then
+        continue
+    fi
+    start_letter=$((start_letter+3))
+    if [ $start_letter -ge ${#line} ]; then
+        start_letter=$((start_letter - ${#line}))
+    fi
+    if [ "${line:$start_letter:1}" = "#" ]; then
+        tree_count=$((tree_count+1))
+    fi
+done
+
+echo "Hit $tree_count trees"
+
+exit 0
+
+#!/usr/bin/python3
+
+trees_count = 0
+position = 3 # forth square in, we moved 3 right from where we were, 0 + 3 -> 3
+on_first_line = True
+line_number = 0
+
+for line in open("input.txt", "r"):
+    line_number += 1
+    print("line: ", line_number)
+    line = line.rstrip()
+    print(line)
+    if on_first_line:
+        on_first_line = False
+        continue
+    print(line[position], position)
+    if line[position] == "#":
+        trees_count += 1
+        print("hit tree")
+    else:
+        print("missed tree")
+    # now add 3 to the position
+    position += 3
+    if position >= len(line):
+        position = position - len(line)
+
+print("There were", trees_count, "trees")