--- /dev/null
+
+package day3
+
+import (
+ "fmt"
+ "os"
+ "io"
+ "bufio"
+ //"strings"
+ //"strconv"
+)
+
+type BitCount struct {
+ zero, one int
+}
+
+/*
+func CountBits (x int) (bc []BitCount) {
+ for i := 0; i < 32; i++ {
+ if x & 1<<i == 1 { bc.zero++ }
+ }
+}
+*/
+
+func parseDiag(r io.Reader) ([]BitCount, error) {
+ s := bufio.NewScanner(r)
+
+ if ok := s.Scan(); !ok { return nil, nil }
+
+ line := s.Text()
+ n := len(line)
+ bc := make([]BitCount, n)
+
+ for {
+ //fmt.Printf("%v\n", line)
+ for i, c := range line {
+ switch c {
+ case '0':
+ bc[n-1-i].zero++
+ case '1':
+ bc[n-1-i].one++
+ default:
+ return nil, fmt.Errorf("Wrong input")
+ }
+ }
+ //fmt.Printf("%v\n", bc)
+ if ok := s.Scan(); !ok { break }
+ line = s.Text()
+ }
+ return bc, nil
+}
+
+func f1(bc []BitCount) (gamma uint32, epsilon uint32) {
+ n := len(bc)
+ for i := 0; i < n; i++ {
+ //fmt.Printf("bc=%#v\n", bc[i])
+ if bc[i].one > bc[i].zero {
+ //fmt.Printf("one at %d\n", i)
+ gamma |= 1<<i
+ }
+ }
+ t := 32 - n
+ // FIXME: Does uint rquired?
+ epsilon = (^gamma<<t)>>t
+ return
+}
+
+func RunF1(input string) {
+ h0, err := os.Open(input)
+ if err != nil { return }
+ defer h0.Close()
+
+ bc, err := parseDiag(h0)
+ if err != nil {
+ fmt.Printf("Error: %v\n", err)
+ return
+ }
+ //fmt.Printf("bc=%#v\n", bc)
+ gamma, epsilon := f1(bc)
+ //fmt.Printf("%0b\n", (^t<<27)>>27)
+
+ fmt.Printf("Answer1: %d (%d, %d)\n", gamma * epsilon, gamma, epsilon)
+}
+
import (
//"sgf-dma/aoc-2021/day1"
- "sgf-dma/aoc-2021/day2"
+ //"sgf-dma/aoc-2021/day2"
+ "sgf-dma/aoc-2021/day3"
)
func main() {
//day1.RunF1("day1/input.txt")
//day1.RunF2("day1/input.txt")
- day2.RunF1("day2/input.txt")
- day2.RunF2("day2/input.txt")
+ day3.RunF1("day3/input.txt")
+ //day2.RunF2("day2/input.txt")
}
projects / aoc-2021.git / commitdiff