Merge branch 'day03'

day03/engine-schema.go

@@ -0,0 +1,142 @@
+package main
+
+import (
+    "fmt"
+//    "strings"
+    "bufio"
+    "os"
+    "regexp"
+    "strconv"
+)
+
+func check(e error) {
+    if e != nil {
+        panic(e)
+    }
+}
+
+func PrintAndWait(x ...any) {
+    fmt.Print(x)
+    fmt.Scanln() 
+}
+
+func main() {
+	file, err := os.Open("./inputs/day03_input")
+	check(err)
+	defer file.Close()
+
+	// This regex find the numbers inside strings
+	renum := regexp.MustCompile("[0-9]+")
+	resym := regexp.MustCompile("[^0-9.]+")
+
+	scanner := bufio.NewScanner(file)
+	var lines []string
+	var totalSum int = 0
+
+	// Read the whole file into an array of strings
+	for scanner.Scan() {
+    	lines = append(lines, scanner.Text())
+	}
+	numLines := len(lines)
+	numbers := make([][]int, numLines)
+
+	// The 2D array of numbers will hold all the numbers to easily
+	// match them with corresponding strings in the file using the index
+	// For every line in the file, cerate an array of numbers
+	for i := 0; i < numLines; i++ {
+    	tempNums := renum.FindAllString(lines[i], -1)
+    	for j := 0; j < len(tempNums); j++ {
+    		num, _ := strconv.Atoi(tempNums[j])
+    		numbers[i] = append(numbers[i], num)
+    	}
+	}
+	/* 	Line [0] needs to check only line 1 for symbols.
+		Similarly, the last line needs to check only
+		(last line index - 1) for symbols.
+		So we first check the line [0], then start a loop
+		from 1 to (last line index - 1)
+	*/
+	firstLineNums 			:= renum.FindAllStringIndex(lines[0], -1)
+	firstLineSymbolsIndex 	:= resym.FindAllStringIndex(lines[0], -1)
+	secondLineSymbolsIndex 	:= resym.FindAllStringIndex(lines[1], -1)
+	// For every *number index range*, check if in the same line there is a
+	// symbol on (first - 1) or (last + 1), check in other lines if there is
+	// a symbol in a specific interval of numbers. If you find a match, you
+	// can break as you just need one symbol
+	for i := range firstLineNums {
+    	for j := range firstLineSymbolsIndex {
+			if firstLineSymbolsIndex[j][0] >= firstLineNums[i][0] - 1 &&
+			   (firstLineSymbolsIndex[j][0] <= firstLineNums[i][1]) {
+    			   totalSum += numbers[0][i]
+    			   break
+			   }
+    	}
+    	for j := range secondLineSymbolsIndex {
+			if (secondLineSymbolsIndex[j][0] >= firstLineNums[i][0] - 1)  &&
+			   (secondLineSymbolsIndex[j][0] <= firstLineNums[i][1]) {
+    			   totalSum += numbers[0][i]
+    			   break
+			   }
+    	}
+	}
+	// Now we loop from 1 to (last index - i)
+	for i := 1; i < len(lines) - 1; i++ {
+    	// We need to check the current line against an interval of three lines
+    	// breaking the loop for a single number as soon as we find a match
+    	// (we don't want duplicate matches)
+    	currentLineNums := renum.FindAllStringIndex(lines[i], -1)
+    	previousLineIndex := resym.FindAllStringIndex(lines[i - 1], -1)
+    	currentLineIndex := resym.FindAllStringIndex(lines[i], -1)
+    	nextLineIndex := resym.FindAllStringIndex(lines[i + 1], -1)
+OuterLoop:
+    	for k := range currentLineNums {
+    		for j := range previousLineIndex {
+        		if previousLineIndex[j][0] >= currentLineNums[k][0] - 1 &&
+        			previousLineIndex[j][0] <= currentLineNums[k][1] {
+            			totalSum += numbers[i][k]
+            			continue OuterLoop
+        			} 
+    		}
+    		for j := range currentLineIndex {
+        		if currentLineIndex[j][0] >= currentLineNums[k][0] - 1 &&
+        			currentLineIndex[j][0] <= currentLineNums[k][1] {
+            			totalSum += numbers[i][k]
+            			continue OuterLoop
+        			} 
+    		}
+    		for j := range nextLineIndex {
+        		if nextLineIndex[j][0] >= currentLineNums[k][0] - 1 &&
+        			nextLineIndex[j][0] <= currentLineNums[k][1] {
+            			totalSum += numbers[i][k]
+            			continue OuterLoop
+        			} 
+    		}
+    	}
+	}
+	// Now we need to loop the last line and confront it with previous
+	// and itself
+	lastLineNums 			:= renum.FindAllStringIndex(lines[len(lines) - 1], -1)
+	lastLineSymbolsIndex 	:= resym.FindAllStringIndex(lines[len(lines) - 1], -1)
+	notLastLineSymbolsIndex 	:= resym.FindAllStringIndex(lines[len(lines) - 2], -1)
+	// For every *number index range*, check if in the same line there is a
+	// symbol on (last - 1) or (last + 1), check in other lines if there is
+	// a symbol in a specific interval of numbers. If you find a match, you
+	// can break as you just need one symbol
+	for i := range lastLineNums {
+    	for j := range lastLineSymbolsIndex {
+			if lastLineSymbolsIndex[j][0] >= lastLineNums[i][0] - 1 &&
+			   (lastLineSymbolsIndex[j][0] <= lastLineNums[i][1]) {
+    			   totalSum += numbers[len(lines) - 1][i]
+    			   break
+			   }
+    	}
+    	for j := range notLastLineSymbolsIndex {
+			if (notLastLineSymbolsIndex[j][0] >= lastLineNums[i][0] - 1) &&
+			   (notLastLineSymbolsIndex[j][0] <= lastLineNums[i][1]) {
+    			   totalSum += numbers[len(lines) - 1][i]
+    			   break
+			   }
+    	}
+	}
+	fmt.Printf("The total sum is: %d\n", totalSum)
+}

day03/inputs

@@ -0,0 +1 @@
+../inputs