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www.mikescher.com/www/statics/aoc/2021/03_solution.go

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2021-12-03 09:16:02 +01:00
package advent
import (
"AdventOfCode2021/util"
"fmt"
"strconv"
)
func Day03Part1(ctx *util.AOCContext) (string, error) {
gamma := ""
epsilon := ""
for i := 0; i < 12; i++ {
mc, lc := getMostAndLeastCommonBit(ctx.InputLines(), i)
gamma += string(mc)
epsilon += string(lc)
}
intGamma, err := strconv.ParseInt(gamma, 2, 64)
if err != nil {
return "", err
}
intEpsilon, err := strconv.ParseInt(epsilon, 2, 64)
if err != nil {
return "", err
}
return fmt.Sprintf("%d", intGamma*intEpsilon), nil
}
func Day03Part2(ctx *util.AOCContext) (string, error) {
var err error
resOxy := int64(-1)
resCO2 := int64(-1)
valOxy := ctx.InputLines()
valCO2 := ctx.InputLines()
for i := 0; i < len(ctx.InputLines()[0]); i++ {
oxy, _ := getMostAndLeastCommonBit(valOxy, i)
_, co2 := getMostAndLeastCommonBit(valCO2, i)
ctx.Printf("MCB[Oxy]: %v\n\n", string(oxy))
ctx.Printf("LCB[CO2]: %v\n\n", string(co2))
newOxy := make([]string, 0)
newCO2 := make([]string, 0)
for _, v := range valOxy {
if v[i] == oxy {
newOxy = append(newOxy, v)
}
}
valOxy = newOxy
for _, v := range valCO2 {
if v[i] == co2 {
newCO2 = append(newCO2, v)
}
}
valCO2 = newCO2
if len(valOxy) == 1 {
resOxy, err = strconv.ParseInt(valOxy[0], 2, 64)
if err != nil {
return "", err
}
ctx.Printf("Oxy := %v\n\n", resOxy)
}
if len(valCO2) == 1 {
resCO2, err = strconv.ParseInt(valCO2[0], 2, 64)
if err != nil {
return "", err
}
ctx.Printf("CO2 := %v\n\n", resCO2)
}
ctx.Printf("CO2:\n%v\n\n", valCO2)
ctx.Printf("Oxy:\n%v\n\n", valOxy)
}
ctx.Printf("Result := %v * %v = %v\n\n", resOxy, resCO2, resOxy*resCO2)
return fmt.Sprintf("%d", resOxy*resCO2), nil
}
func getMostAndLeastCommonBit(lines []string, pos int) (uint8, uint8) {
count0 := 0
count1 := 0
for _, line := range lines {
if line[pos] == '0' {
count0++
} else {
count1++
}
}
if count1 >= count0 {
return '1', '0'
} else {
return '0', '1'
}
}