Introduction

Santa was hoping for a white Christmas, but his weather machine’s “snow” function is powered by stars, and he’s fresh out! To save Christmas, he needs you to collect fifty stars by December 25th.

Collect stars by helping Santa solve puzzles. Two puzzles will be made available on each day in the Advent calendar; the second puzzle is unlocked when you complete the first. Each puzzle grants one star. Good luck!

Here’s an easy puzzle to warn you up.

Problem

Santa is trying deliver presents in a large apartment building, but he can’t find the right floor - the directions he got are a little confusing. He starts on the ground floor (floor 0) and then follows the instructions on character at a time.

An opening parenthesis, (, means he should go up one floor, and a closing parenthesis ), means he should go down one floor.

The apartment building is very tall, and the basement is very deep; he will never find the top or bottom floors.

For example:

• (()) and ()() both result in floor 0.
• ((( and (()(()( both result in floor 3.
• ))((((( also results in floor 3.
• ()) and ))( both result in floor -1 (the first basement level).
• ))) and )())()) both result in floor -3.

To what floor do the instructions take Santa?

Problem Set

()()(()()()(()()((()((()))((()((((()()((((()))()((((())(((((((()(((((((((()(((())(()()(()((()()(()(())(()((((()((()()()((((())((((((()(()(((()())(()((((()))())(())(()(()()))))))))((((((((((((()())()())())(())))(((()()()((((()(((()(()(()()(()(()()(()(((((((())(())(())())))((()())()((((()()((()))(((()()()())))(())))((((())(((()())(())(()))(()((((()())))())((()(())(((()((((()((()(())())))((()))()()(()(()))))((((((((()())((((()()((((()(()())(((((()(()())()))())(((()))()(()(()(()((((()(())(()))(((((()()(()()()(()(((())())(((()()(()()))(((()()(((())())(()(())())()()(())()()()((()(((()(())((()()((())()))((()()))((()()())((((()(()()(()(((()))()(()))))((()(((()()()))(()(((())()(()((()())(()(()()(()())(())()(((()(()())()((((()((()))))())()))((()()()()(())()())()()()((((()))))(()(((()()(((((((())()))()((((()((())()(()())(())()))(()(()())(((((((())))(((()))())))))()))())((())(()()((())()())()))))()((()()())(())((())((((()())())()()()(((()))())))()()))())(()()()(()((((((()()))())()))()(((()(((())((((()()()(()))())()()))))())()))())((())()())(((((())())((())())))(((())(((())(((((()(((((())(()(()())())(()(())(()))(()((((()))())()))))())))((()(()))))())))(((((())()))())()))))()))))(((()))()))))((()))((()((()(()(())()())))(()()()(())()))()((((())))))))(())(()((()()))(()))(()))(()((()))))))()()((((()()))()())()))))))()()()))(()((())(()))((()()()())()(((()((((())())))()((((()(()))))))())))()()())()))(()))))(()())()))))))((())))))))())()))()((())())))(()((()))()))(())))))(()))()())()()))((()(()))()()()()))))())()()))())(())()()))()))((()))))()()(()())))))()()()))((((()))()))))(()(())))(()())))((())())(()))()))))()())))()())()())))))))))()()))))())))((())((()))))())))(((()())))))))(()))()()))(()))()))))()())))))())((((()())))))))())))()()))))))))()))()))))()))))))(())))))))))())))))))))))))))())())((())))))))))()))((())))()))))))))())()(()))))))())))))()()()())()(()()()(()())(()))()()()(()())))())())))()))))())))))))()()()()())(())())()())()))))(()()()()()))))()))())())))((()())()())))()))()))))(()())))()))))))))(((()))()()))))))))))))))))))))(()))(()((()))())))())(()))(()(()(())))))()(()))()))()()))))))))))))()((()())(())())()(())))))())()())((()()))))(()()))))())()(())()))))))))))))))))))))()))(()(()())))))))()()((()))()))))))((())))()))))))))((()))())()()))())()()))((()))())))))))))))(()())()))(())((()(()()))(()())(())))()())(()(())()()))))()))()(()))))))(()))))))))))(()))())))))))))())))))())))(())))))()))))(())())))))))))()(()))))()())))())(()))()())))))))))))))())()()))))()))))))())))))()))))(())(()()()()((())()))())(()))((())()))())())(())(()()))))()))(())()()((())(())))(())))()))())))))))))()(((((())())))(())()))))(())))((()))()(((((((()))))()()))(())))))()(()))))(()()))()))())))))))(()())()))))))))())))(()))())()))(())()((())())()())())(()(()))))()))))))((()())(())()()(()())))()()))(())(())(()))())))()))(()))()()))((((()))))()))((()()()))))()))()))())))(()))()))))(())))()))())()(()))()())))())))))))())))())))()()))))))(()))())())))()))()()())())))))))))))))())))()))(()()))))())))())()(())))())))))))))))))))))()()())())))))()()()((()(()))()()(())()())()))()))))()()()))))))((()))))))))()(()(()((((((()()((()())))))))))))()))())))))((())())(()))())))())))))())()()())(())))())))()())())(())))))))()()(())))()))())))())())())()))))))))()))(()()()())())())))(())())))))))()()())()))))())))())()(())())))))))()())()))(()()(())())))()(()((()()((()()(((((())(()())()))(())()))(())))(())))))))()))()))((()))()))()))))))))()))))))))((()()())(()))(((()))(())))()))((())(((())))()())))())))))((())))))(())())((((((())())()(()))()(()((()())))((())()(()(()))))(())(()()())(())))())((()(((())())))(((()())())))())()(())())((((()()))))())((()))()()()()(())(((((((()()()((()))())(()())))(())())((((()()(()))))()((())))((())()))()(((()))())))()))((()(()))(())(()((((())((((()()(()()))(((())(()))))((((()(()))(())))))((()))(()))((()(((()(()))(()(()((()(())(()(()(()(()()((()))())(((())(()(()))))(()))()()))(())))(())()(((())(()))()((((()()))))())(()))))((())()((((()(((()))())())(((()))()())((())(())())(())()(())()(()()((((((()()))))()()(((()()))))()())()(((()(()))(()(()())(()(()))))(((((()(((())())))))(((((()((()()((())())((((((()(())(()()((()()()()()()()(()()))()(((()))()))(((((((())(((()((()())()((((())(((()(())))()((()(()()()((())((()())()))()))())))())((((((()))(()(()()()))(()((()(()(()))()((()(((()()()((())(((((())()(()))())())((()(())))(()(()())(())((())())())(((()()()(())))))())(()))))))()))))))())((()()()))((()((((((()))(((()((((()()()(((()))())()(()()(((()((()()()()())()()))()()()(()(())((()))))(()))())))))))()(()()(((((())()(()(((((()((()(()()())(()((((((((()((((((())()((((()()()((()((()((((((()))((())))))))())()))((()(()))()(()()(()((())((()()((((((((((((()())(()()()))((((()((((((())(()))())(()()((()()))()(((((((()((()()((((((()(((())))((())))((((((((()()(((((((())(((((()())(((())((())()((((()(((((((()(()(((()((((((()(((()(((((((((((()()((()()(()))((()()(((()(((())))((((())()(()(((())()(()(((())(((((((((((()))())))((((((())((()()((((()())())((((()()))((())(((((()(()()(()()()((())(()((()()((((()(((((()((()(()((((()())((((((()(((((()()(()(()((((())))(())(())(())((((()(()()((((()((((()()((()((((((())))(((((()))))()))(()((((((((()(((())())(((())))(()(()((())(((()((()()(((((()((()()(((())()(()))(((((((())(()(((((()))((()((()((()))(())())((((()((((())()(()))(((()(((((((((((((((())(((((((((()))(((()(()()()()((((((()((())()((((((((()(())(((((((((((()(()((())()((()()(()(()()((((()()((())(()((()()(()()((((()(((((((())))((((())(())()(((()()((()()((((()((()(((()((())(((()()()((((()((((()()(()(()((((((((())(()(((((())(()())(((((((()())()(()((((()((())(()()())((((()()(((()((((())(())(()()(((((((((()()))()(((())(()(()((((((())(()()())(()))()()(((()(((()((())(()(((((((()(()(()((()(((((()(()((()(()((((((()((((()()((((()(((()((())(()(()((()()((((()()(())()(())(((())(()((((((((()())(((((((((()(())()((((())))()))()()(((((()()((((((())(()()(((()(()(((((((()(()(((((((())(())((((()((()(())))((((()()())(()))((()())((((()(((((()(()(())(()(()()())(((((()(((((()((((()()((((((((()()))(()((((((())((((())()(()(((()()()(((()(()(())(())(((((()(())())((((())(())(()(((()(((((())((((())())((()(((((((()(((())(()(()))(((((((((()((()((()()(()((((())(((()((())((((())(()(((()(((()(()((((()(((())(()(((()(()()(()(()((()()(()())(())())((()(()(((()(((()(((()()(((((((((()(((((((((()()(((()(((()())((((()(()(((()()()((())((((((((((())(()(((()((((()())((((()((()))(((()()()(((((()(((((((())((()())(()((((())((((((((())(()((()((((((((((()()((()((()()))(((()())()())()(((()())()()(()(()(((((((())()))(())()))())()()((())()((()((((()((()((())(((((()((((((()(())))(()))())(((()))((()()(()(((()))((((())()(((()))))()(()(())()(((((())(()(()(())(())()((()()()((((()(())((()())(()(()))(()(()(()()(())()()(()((())()((()))))()))((()(()()()()((()())(()))())()(()(((((((((())())((()((()((((((())()((((())(((())((()(()()()((())(()((())(((()((((()()((()(()(((((())()))()((((((()))((())(((()()))(((())(())()))(((((((())(())())()(())(((((()))()((()))()(()()((()()()()()())(((((((

Solution

Iterate the characters in the file, determining the sum or difference of floors with respect to the starting ground floor, 0.

Steps

• Create a variable, holding the current floor number.
• Read the file contents.
• Increment the floor number upon finding an opening parenthesis, (.
• Decrement the floor number upon finding a closing parenthesis, ).
• Return the solution as the current floor number.

Implementation

c (v1)

int main(void) {
    int s = 0;
    FILE *fp;
    char c;

    fp = fopen("./input.txt", "r");
    if (NULL == fp) {
        printf("cannot open file\n");
        return EXIT_FAILURE;
    }

    while ((c = fgetc(fp)) != EOF) {
        if (c == '(') {
            s += 1;
        } else if (c == ')') {
            s -= 1;
        }
    }
    fclose(fp);

    printf("floor_number: %d\n", s);
    return 0;
}

zig (v1)

pub fn main() !void {
    var gpa = std.heap.GeneralPurposeAllocator(.{}){};
    const alc = gpa.allocator();
    defer {
        _ = gpa.deinit();
    }

    const f = try std.fs.openFileAbsolute("/Users/tymalik/Documents/git/void/zig/aoc_2015_001/src/input.txt", .{ .mode = .read_only });
    defer f.close();

    var b = std.io.bufferedReader(f.reader());
    var r = b.reader();

    var a = std.ArrayList(u8).init(alc);
    defer a.deinit();

    var s: i32 = 0;
    while (true) {
        r.streamUntilDelimiter(a.writer(), '\n', null) catch |e| switch (e) {
            error.EndOfStream => break,
            else => return e,
        };
    }

    for (a.items) |c| {
        if (c == '(') {
            s += 1;
        } else if (c == ')') {
            s -= 1;
        }
    }

    a.clearRetainingCapacity();
    std.debug.print("floor_number: {d}\n", .{s});
}

rust (v1)

fn main() -> io::Result<()> {
    let mut s: i32 = 0;
    let mut f = File::open("./src/input.txt")?;
    let mut bv = Vec::new();

    f.read_to_end(&mut bv)?;

    let cv: Vec<char> = bv.iter().map(|b| *b as char).collect::<Vec<_>>();

    for c in cv.iter() {
        if *c == '(' {
            s += 1;
        } else if *c == ')' {
            s -= 1;
        }
    }
    println!("floor_number: {}", s);
    Ok(())
}

go (v1)

package main

import (
	"fmt"
	"os"
)

func main() {
	s := 0

	f, e := os.ReadFile("./input.txt")
	if e != nil {
		panic(e)
	}

	for _, v := range f {
		if string(v) == "(" {
			s += 1
		} else if string(v) == ")" {
			s -= 1
		}
	}

	fmt.Printf("floor_number: %d\n", s)
}