re: AoC Day 1: Chronal Calibration VIEW POST

FULL DISCUSSION
 

I am using Advent of Code to learn Golang, and here is the solution I came up with. Suggestions for improvements are always welcome!

Part 1:

package main

import (
    "bufio"
    "fmt"
    "os"
    "strconv"
)

// readLines reads a whole file into memory
// and returns a slice of its lines.
func readLines(path string) ([]int, error) {
    file, err := os.Open(path)
    if err != nil {
        return nil, err
    }
    defer file.Close()

    var lines []int
    scanner := bufio.NewScanner(file)
    for scanner.Scan() {
        // string to int
        i, err := strconv.Atoi(scanner.Text())
        if err != nil {
            return nil, err
        }
        lines = append(lines, i)
    }
    return lines, scanner.Err()
}

func main() {
    lines, err := readLines("input")
    if err != nil {
        panic(err)
    }

    var sum int
    for _, line := range lines {
        sum += line
    }
    fmt.Printf("Sum is: %d\n", sum)
}

Part 2:

package main

import (
    "bufio"
    "fmt"
    "os"
    "strconv"
)

// readLines reads a whole file into memory
// and returns a slice of its lines.
func readLines(path string) ([]int, error) {
    file, err := os.Open(path)
    if err != nil {
        return nil, err
    }
    defer file.Close()

    var lines []int
    scanner := bufio.NewScanner(file)
    for scanner.Scan() {
        // string to int
        i, err := strconv.Atoi(scanner.Text())
        if err != nil {
            return nil, err
        }
        lines = append(lines, i)
    }
    return lines, scanner.Err()
}

func main() {
    lines, err := readLines("input")
    if err != nil {
        panic(err)
    }

    occurences := map[int]int{0: 1}
    var freq, j int
    for occurence := 1; occurence < 2; j++ {
        freq += lines[j%len(lines)]
        _, ok := occurences[freq]
        if ok {
            occurence = 2
        }
        occurences[freq] = 1
    }
    fmt.Printf("%d\n", freq)
}

I am also using Python that I have more experience with to cross check solutions.

Part 1:

def chronal_calibration(fname):
    with open(fname) as f:
        content = f.readlines()
    return sum([int(x.strip()) for x in content])


chronal_calibration('input')

Part 2

import itertools

def chronal_calibration_cycle(fname):
    with open(fname) as f:
        content = f.readlines()
    content = [int(x.strip()) for x in content]
    freq = 0
    occurences = {freq: 1}
    for change in itertools.cycle(content):
        freq += change
        occurences[freq] = occurences.get(freq, 0) + 1
        if occurences[freq] > 1:
            break
    return freq


print(chronal_calibration_cycle('input'))
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