add day 2 part 1

day2/test_reports.go

@@ -0,0 +1,58 @@
+package main
+
+import (
+    "fmt"
+    "os"
+    "strings"
+    "strconv"
+)
+
+func check(e error) {
+    if e != nil {
+        panic(e)
+    }
+}
+
+func main() {
+    // read in file as lines
+    dat, err := os.ReadFile("data.txt")
+    check(err)
+    lines := strings.Split(string(dat), "\n")
+
+    // valid reports
+    valid := 0
+
+    for i := range len(lines) - 1 {
+        str_levels := strings.Split(lines[i], " ")
+        
+        // convert to integer
+        levels := make([]int, len(str_levels))
+        for j := range str_levels {
+            levels[j], err = strconv.Atoi(str_levels[j])
+            check(err)
+        }
+
+        // check for validity
+        if levels[0] > levels[1] {
+            // decreasing sequence
+            valid += 1
+            for j := range len(levels) - 1 {
+                if levels[j] - levels[j+1] <= 0 || levels[j] - levels[j+1] > 3 {
+                    valid -= 1
+                    break
+                }
+            }
+        } else if levels[0] < levels[1] {
+            // increasing sequence
+            valid += 1
+            for j := range len(levels) - 1 {
+                if levels[j+1] - levels[j] <= 0 || levels[j+1] - levels[j] > 3 {
+                    valid -= 1
+                    break
+                }
+            }
+        }
+    }
+
+    fmt.Println(valid)
+}