First event, first part

20231201/trebuchet.go

@@ -0,0 +1,57 @@
+package main
+
+import (
+    "fmt"
+    "bufio"
+    "os"
+    "strconv"
+)
+
+func check(e error) {
+    if e != nil {
+        panic(e)
+    }
+}
+
+func ExtractCalibration(s string) string {
+
+	firstDigit := 0
+	lastDigit := 0
+	index := 0
+	
+    for i := 0; i < len(s); i++ {
+       if num, err := strconv.Atoi(string(s[i])); err == nil {
+           firstDigit = num
+           index = i
+           break
+       }
+    }
+
+    for j := len(s) - 1; j >= index; j-- {
+       if num, err := strconv.Atoi(string(s[j])); err == nil {
+           lastDigit = num
+           break
+       }
+    }
+   
+    
+    return fmt.Sprint(firstDigit) + fmt.Sprint(lastDigit)
+}
+
+func main() {
+	file, err := os.Open("input")
+	check(err)
+
+	var total int = 0
+
+	scanner := bufio.NewScanner(file)
+
+	for scanner.Scan() {
+    	line := scanner.Text()
+    	calibration := ExtractCalibration(line)
+    	num, err := strconv.Atoi(calibration)
+    	_ = err
+    	total += num
+	}
+	fmt.Println(total) 
+}