Changed folder name from 20231201 to day01

day01/trebuchet.go

@@ -0,0 +1,132 @@
+package main
+
+import (
+    "fmt"
+    "strings"
+    "bufio"
+    "os"
+    "strconv"
+)
+
+var numbers = []string {
+   "one", "two", "three", "four", "five",
+   "six", "seven", "eight", "nine",
+}
+
+// Panic if err
+func check(e error) {
+    if e != nil {
+        panic(e)
+    }
+}
+
+func ExtractCalibration(s string) string {
+
+	firstDigit := 0
+	lastDigit := 0
+	index := 0
+
+	// Start from the beginning of the string, stop when you find a number
+    for i := 0; i < len(s); i++ {
+       if num, err := strconv.Atoi(string(s[i])); err == nil {
+           firstDigit = num
+           index = i
+           break
+       }
+    }
+
+	// Start from the end of the string, stop when you find a number
+    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 SearchFirstIndex(s string) int {
+    // len(s) will always be bigger than the first index where you
+    // can have a substring match
+    index, number := len(s),0
+    // from 1 to 9, save the smallest index and the number
+    for i := 1; i < 10; i++ {
+        tempIndex := strings.Index(s, fmt.Sprint(i))
+        if tempIndex < index && tempIndex != -1 {
+            index = tempIndex
+            number = i
+        }
+
+    }
+    // again for strings, from [0] "one" to [8] "nine"
+    // save the smallest index, if smaller than the previous
+    for i := 0; i < 9; i++ {
+        tempIndex := strings.Index(s, numbers[i])
+        if tempIndex < index && tempIndex != -1 {
+            index = tempIndex
+            number = i + 1
+        }
+    }
+
+    return number
+}
+
+func SearchLastIndex(s string) int {
+    // -1 will always be smaller than the last index where you
+    // can have a substring match
+    index, number := -1,0
+    for i := 1; i < 10; i++ {
+        tempIndex := strings.LastIndex(s, fmt.Sprint(i))
+        if tempIndex > index && tempIndex != -1 {
+            index = tempIndex
+            number = i
+        }
+
+    }
+    for i := 0; i < 9; i++ {
+        tempIndex := strings.LastIndex(s, numbers[i])
+        if tempIndex > index && tempIndex != -1 {
+            index = tempIndex
+            number = i + 1
+        }
+    }
+
+    return number
+}
+
+func CombineIndexes(s string) int {
+    firstNumber := SearchFirstIndex(s)
+    secondNumber := SearchLastIndex(s)
+
+    combinedString := fmt.Sprint(firstNumber) + fmt.Sprint(secondNumber)
+
+    combinedNumber, err := strconv.Atoi(combinedString)
+    _ = err
+
+    return combinedNumber    
+}
+
+func main() {
+	file, err := os.Open("input")
+	check(err)
+	defer file.Close()
+
+	var firstTotal int = 0
+	var secondTotal int = 0
+
+	scanner := bufio.NewScanner(file)
+
+	for scanner.Scan() {
+    	line := scanner.Text()
+    	calibration := ExtractCalibration(line)
+    	num, err := strconv.Atoi(calibration)
+    	_ = err
+    	firstTotal += num
+    	secondTotal += CombineIndexes(line) 
+	}
+	fmt.Printf("Calibration value, first method: %d\n", firstTotal)
+	fmt.Printf("Calibration value, second method: %d\n", secondTotal) 
+	
+}