day09: rust

01/README.md

@@ -3,6 +3,8 @@
 
 Today's language: **Python**
 
+Lines of code: **3**
+
 Execution time: **0,021 s**
 
 Both tasks are solved in one hell of a oneliner each:

02/README.md

@@ -3,6 +3,7 @@
 
 Today's language: **Rust**
 
+Lines of code: **49**
 
 Execution time: **0,002 s**
 

03/README.md

@@ -3,6 +3,8 @@
 
 Today's language: **Rust**
 
+Lines of code: **85**
+
 Execution time: **0,006 s**
 
 ```shell

04/README.md

@@ -3,6 +3,8 @@
 
 Today's language: **Rust**
 
+Lines of code: **40**
+
 Execution time: **0,004 s**
 
 ```shell

05/README.md

@@ -3,6 +3,8 @@
 
 Today's language: **Rust**
 
+Lines of code: **138**
+
 Execution time: **0,009 s**
 
 Super fast!

06/README.md

@@ -3,6 +3,8 @@
 
 Today's language: **Rust**
 
+Lines of code: **60**
+
 Execution time: **0,001 s**
 
 *Midnight formula go brrrrr*

07/README.md

@@ -3,6 +3,8 @@
 
 Today's language: **Rust**
 
+Lines of code: **210**
+
 Execution time: **0,007 s**
 
 Not pretty, but pretty fast.

08/README.md

@@ -3,6 +3,8 @@
 
 Today's language: **Rust**
 
+Lines of code: **101**
+
 Execution time: **0,039 s**
 
 Next time, I should just use 64 bit right from the start...

09/README.md

@@ -0,0 +1,17 @@
+# [Day 9](https://adventofcode.com/2023/day/9) 
+:gift::gift::gift::gift::gift::gift::gift::gift::gift:
+
+Today's language: **Rust**
+
+Lines of code: **88**
+
+Execution time: **0,003 s**
+
+This solution uses a custom triangle datatype.
+It is a bit overkill code-wise, but efficient with memory and re-allocations.
+
+```shell
+rustc day09.rs
+./day09
+```
+<!-- implemented triangle datatype -->

09/day09.rs

@@ -0,0 +1,114 @@
+use std::io::{self, BufRead};
+use std::fmt::Debug;
+use std::fmt;
+
+// 0 1 3 6 10 ...
+fn triangular_numbers(n: usize) -> usize { (n * (n + 1)) / 2 }
+
+struct Triangle {
+    data: Vec::<i32>,
+    width: usize,
+}
+impl Triangle {
+    fn new(firstrow: &mut Vec<i32>) -> Triangle {
+        let mut triangle = Triangle{data: Vec::new(), width: firstrow.len()};
+        triangle.data = std::mem::take(firstrow);
+        triangle.data.resize(triangular_numbers(triangle.width), 0);
+        return triangle
+    }
+    fn at_mut(&mut self, row: usize, col: usize) -> &mut i32 {
+        let i = self._index(row, col);
+        &mut self.data[i]
+    }
+    fn at(&self, row: usize, col: usize) -> i32 {
+        self.data[self._index(row, col)]
+    }
+// 1 2 3 4
+// 1 2 3
+// 1 2
+// 1
+    fn _index(&self, row: usize, col: usize) -> usize {
+        assert!(col < self.row_len(row), "Invalid indices for Triangle with width {}: row={}, col={}", self.width, row, col);
+        return col + self.data.len() - triangular_numbers(self.width - row);  // subtract  the triangle with width (self.width - row) from total length
+    }
+    // fn row(&mut self, row: usize) -> impl Iterator<Item = &mut i32> {
+    //     assert!(row < self.width, "Invalid row");
+    //     let skip: usize = self.width * row - triangular_numbers(self.width - row);  // skip <row> rows - the triangle with width (self.width - row)
+    //     self.data.iter_mut().skip(skip).take(self.row_len(row));
+    // }
+    // #rows or #colums of first row
+    fn len(&self) -> usize { self.width }
+    fn row_len(&self, row: usize) -> usize { self.width - row }
+}
+impl fmt::Display for Triangle {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        for r in 0..self.len() {
+            for c in 0..self.row_len(r) {
+                let res = write!(f, "{} ", self.at(r, c));
+                if res.is_err() { return res };
+            }
+            if r != self.len() - 1 { println!() }
+        }
+        return Result::Ok(());
+    }
+}
+
+fn predict(numbers: &mut Vec<i32>) -> (i32, i32) {
+    numbers.insert(0, 0);
+    numbers.push(0); 
+    let mut triangle = Triangle::new(numbers);
+    // fill until maxrow is all zero
+    let mut maxrow: usize = triangle.len() - 1;  // skip last row
+    for r in 1..maxrow {
+        maxrow = r;
+        let mut allzero = true;
+        for j in 1..triangle.row_len(r) - 1 {
+            // print!("{} -> ", triangle.at(r, j));
+            let diff = triangle.at(r-1, j+1) - triangle.at(r-1, j); //).abs();
+            allzero &= diff == 0;
+            *triangle.at_mut(r, j) = diff;
+        }
+        if allzero { break }
+        // println!();
+    }
+    assert!(maxrow < triangle.len()- 3, "maxrow={} ", maxrow);
+    for r in (0..maxrow).rev() {
+        // forward prediction
+        let newval = triangle.at(r, triangle.row_len(r) - 2) + triangle.at(r + 1, triangle.row_len(r + 1) - 1);
+        *triangle.at_mut(r, triangle.row_len(r) - 1) = newval;
+
+        let newval = triangle.at(r, 1) - triangle.at(r + 1, 0);
+        *triangle.at_mut(r, 0) = newval;
+    }
+    // println!("{}", triangle);
+    return (triangle.at(0, 0), triangle.at(0, triangle.row_len(0) - 1));
+}
+
+fn main() {
+    let input = "input.txt";
+    // let input = "example.txt";
+    let lines = read_lines(&input);
+    let mut sum_forward_predictions = 0;
+    let mut sum_backward_predictions = 0;
+    for line in lines.map(|r| r.ok().unwrap()) {
+        let preds = predict(&mut split_into_numbers::<i32>(&line).collect());
+        sum_backward_predictions += preds.0;
+        sum_forward_predictions += preds.1;
+    }
+    println!("OASIS: sum of forward  predictions (1): {}", sum_forward_predictions);
+    println!("OASIS: sum of backward predictions (2): {}", sum_backward_predictions);
+}
+
+
+fn split_into_numbers<T: std::str::FromStr>(x: &str) -> impl Iterator<Item = T> + '_ where <T as std::str::FromStr>::Err: Debug {
+    return x.split(' ').filter(|&n| {n != "" && n != " "}).map(|n| n.parse::<T>().unwrap());
+}
+
+
+fn read_lines<P>(filename: P) -> io::Lines<io::BufReader<std::fs::File>>
+where P: AsRef<std::path::Path>, {
+    return match std::fs::File::open(filename) {
+        Err(why) => panic!("Could not open file. {}", why),
+        Ok(file) => std::io::BufReader::new(file).lines()
+    };
+}

README.md

@@ -2,13 +2,16 @@
 This is a repository for my solutions for the [advent of code 2023](https://adventofcode.com/2023).
 
 <!-- table begin -->
-| Day      | Language | Execuction time | Comment                     |
+| Day      | Language | Lines of code | Execuction time | Comment                       |
-|:---:     |:---:     | ---:            | ---                         |
+|:---:     |:---:     | ---:          | ---             |                               |
-| [01](01) | Python   | 0,021 s         | one-liners                  |
+| [01](01) | Python   | 3             | 0,021 s         | one-liners                    |
-| [02](02) | Rust     | 0,002 s         | my very first rust program  |
+| [02](02) | Rust     | 49            | 0,002 s         | my very first rust program    |
-| [03](03) | Rust     | 0,006 s         |                             |
+| [03](03) | Rust     | 85            | 0,006 s         |                               |
-| [04](04) | Rust     | 0,004 s         |                             |
+| [04](04) | Rust     | 40            | 0,004 s         |                               |
-| [05](05) | Rust     | 0,009 s         | very efficient              |
+| [05](05) | Rust     | 138           | 0,009 s         | very efficient                |
-| [06](06) | Rust     | 0,001 s         | quadratic formula go *brrr* |
+| [06](06) | Rust     | 60            | 0,001 s         | quadratic formula go *brrr*   |
-| [07](07) | Rust     | 0,007 s         | not pretty, but pretty fast |
+| [07](07) | Rust     | 210           | 0,007 s         | not pretty, but pretty fast   |
-| [08](08) | Rust     | 0,039 s         |                             |
+| [08](08) | Rust     | 101           | 0,039 s         |                               |
+| [09](09) | Rust     | 88            | 0,003 s         | implemented triangle datatype |
+
+ Lines of code are without blank lines and comments

make_day_readme.sh

@@ -15,11 +15,14 @@ function find_lang {
     # 1: fileext, 2: lang, 3: howto
     sourcefile=$(ls $day_dir/*.$1 2> /dev/null)
     [[ $? != 0 ]] && return
-    sourcefile=$(basename $sourcefile)
+    lang=$2
-    printf "$FMT_VAR" "Determined Langugae" "$2 ($sourcefile)"
+    sourcefilebase=$(basename $sourcefile)
+    printf "$FMT_VAR" "Determined Langugae" "$2 ($sourcefilebase)"
     sed -i "s/LANG/$2/" $readme
-    howto=$(echo "$3" | sed "s|SOURCE|$sourcefile|")
+    howto=$(echo "$3" | sed "s|SOURCE|$sourcefilebase|")
     sed -i "s(HOWTORUN($howto(" $readme
+    loc=$(sed -r '/^\s*(#|\/\/|\/\*|;)/d;/^\s*$/d' $sourcefile | wc -l)
+    sed -i "s(LOC($loc(" $readme
 }
 
 function get_time {
@@ -28,6 +31,7 @@ function get_time {
     exe=$(basename $exe)
     if [[ $(echo $exe | wc -w) != 1 ]]; then
         printf "$FMT_ERR" "Found multiple or no executables for day $day: '$exe'"
+        cd ..
         return 1
         time=Error
     else
@@ -37,6 +41,7 @@ function get_time {
             printf "\e[34m"
             echo -e "$time"
             printf "\e[0m"
+            cd ..
             return 1
         fi
         time=$(echo -e "$time" | tail -3 | head -1 | awk '{print $2}')
@@ -50,6 +55,7 @@ function get_time {
         else
             time="$sec,$msec s"
         fi
+        cd ..
         # elif [[ $sec != 0 ]]; then
         #     time="$sec,$msec s"
         # else
@@ -74,8 +80,6 @@ else
     sed -i '/.*EXECTIME.*/d' $readme
 fi
 
-
-
 if [[ -z $1 ]]; then
     printf "$FMT_WARN" "No comment provided"
     sed -i "/<!-- COMMENT -->/d" $readme

make_readme.sh

@@ -1,15 +1,17 @@
 #!/bin/bash
 
-table="| Day | Language | Execuction time | Comment |\n"
+table="| Day | Language | Lines of code | Execuction time | Comment |\n"
 table+="|:---:|:---:| ---:| --- |\n"
 for day in $(seq -f "%02g" 1 25); do
     [[ ! -d "$day" ]] && continue
     # echo $day
     lang=$(grep -E "Today's language:" $day/README.md | sed -r 's/.*\*\*(.+)\*\*.*/\1/')
     exectime=$(grep -E "Execution time:" $day/README.md | sed -r 's/.*\*\*(.+)\*\*.*/\1/')
+    loc=$(grep -E "Lines of code:" $day/README.md | sed -r 's/.*\*\*(.+)\*\*.*/\1/')
     comment=$(grep -E "<!-- .* -->" $day/README.md | head -1 | sed -r 's/.*<!-- *(.*) *-->.*/\1/')
-    table+="| [$day]($day) | $lang | $exectime | $comment |\n"
+    table+="| [$day]($day) | $lang | $loc | $exectime | $comment |\n"
 done
 # remove table from readme
 sed -i '/<!-- table begin -->/q' README.md
 echo -e $table | column -t -s '|' -o '|' >> README.md
+echo -e "\n Lines of code are without blank lines and comments" >> README.md