add aoc2024 day 1 solns

go/.gitignore

@@ -0,0 +1 @@
+input/*.txt

go/cmd/part1/main.go

@@ -0,0 +1,55 @@
+package main
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+	"slices"
+	"strconv"
+	"strings"
+)
+
+func main() {
+  left := []int64{};
+  right := []int64{};
+  reader := bufio.NewReader(os.Stdin)
+
+  for {
+    raw, _, _ := reader.ReadLine()
+    line := string(raw)
+    if strings.Trim(line, " ") == "" {
+      break
+    }
+
+    values := strings.Split(line, "   ")
+
+    l, _ := strconv.ParseInt(values[0], 10, 64)
+    r, _ := strconv.ParseInt(values[1], 10, 64)
+
+    left = append(left, l)
+    right = append(right, r)
+  }
+
+  ans := part1(&left, &right)
+
+  fmt.Println("", ans)
+}
+
+func part1(left *[]int64, right *[]int64) int64 {
+  slices.SortFunc(*left, func (a, b int64) int { return int(a - b); });
+  slices.SortFunc(*right, func (a, b int64) int { return int(a - b); });
+
+  var sum int64 = 0
+
+  sz := len(*left)
+
+  for i := 0; i < sz; i++ {
+    diff := (*left)[i] - (*right)[i]
+    if diff < 0 {
+      diff = diff * -1
+    }
+    sum += diff
+  }
+
+  return sum;
+}

go/cmd/part2/main.go

@@ -0,0 +1,46 @@
+package main
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+	"strconv"
+	"strings"
+)
+
+func main() {
+  left := map[int64]int64{};
+  right := map[int64]int64{};
+  reader := bufio.NewReader(os.Stdin)
+
+  for {
+    raw, _, _ := reader.ReadLine()
+    line := string(raw)
+    if strings.Trim(line, " ") == "" {
+      break
+    }
+
+    values := strings.Split(line, "   ")
+
+    l, _ := strconv.ParseInt(values[0], 10, 64)
+    r, _ := strconv.ParseInt(values[1], 10, 64)
+
+    left[l] = left[l] + 1
+    right[r] = right[r] + 1
+  }
+
+  ans := part2(left, right)
+
+  fmt.Println("", ans)
+}
+
+func part2(left map[int64]int64, right map[int64]int64) int64 {
+  var sum int64 = 0
+
+  for key, l_count := range left {
+    count := right[key]
+    sum += l_count * count * key
+  }
+
+  return sum;
+}

go/go.mod

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+module aoc_2024/day1
+
+go 1.23.4