Initial

Cargo.toml

@@ -0,0 +1,8 @@
+[package]
+name = "cular"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]

src/main.rs

@@ -0,0 +1,148 @@
+use std::env;
+
+fn main() {
+    let args: Vec<String> = env::args().skip(1).take(3).collect();
+    let mut points: [[f64; 2]; 3] = [[0.0; 2]; 3];
+
+    for (i, part) in args.iter().enumerate().take(3) {
+        let values: Vec<f64> = part
+            .split(':')
+            .filter_map(|s| s.parse().ok())
+            .collect();
+
+        if values.len() == 2 {
+            points[i][0] = values[0];
+            points[i][1] = values[1];
+        } else {
+            println!("Invalid input format: {}", part);
+        }
+    }
+    group_by_x(&mut points);
+
+    let m1 = (points[0][1] - points[1][1]) / (points[0][0] - points[1][0]);
+    if m1 == (points[1][1] - points[2][1]) / (points[1][0] - points[2][0]) {
+        println!("{}", straight_string(m1, &points));
+    } else {
+        println!("{}", square_string(&points));
+    }
+}
+
+fn group_by_x(arr: &mut [[f64;2];3]) {
+    arr.sort_by(|a, b| a[0].partial_cmp(&b[0]).unwrap_or(std::cmp::Ordering::Equal));
+}
+
+fn nearest_to_zero(arr: &[[f64;2];3]) -> usize {
+    let mut nearest = arr[1][1];
+    let mut nearest_index = 0;
+    for (i, point) in arr.iter().enumerate() {
+        if nearest < point[1].abs() {
+            nearest = point[i-1];
+            nearest_index = i-1;
+        }
+    }
+    nearest_index
+}
+
+fn straight_string(m: f64, points: &[[f64;2];3]) -> String {
+    format!(
+        "{}x{}",
+        if m != 1.0 {
+            format!("{} * ", m)
+        } else {
+            "".to_string()
+        },
+        {
+            let lowest_y = nearest_to_zero(points);
+            let result = points[lowest_y][0] - points[lowest_y][1] * m;
+            if result != 0.0 {
+                format!(
+                    "{}{}",
+                    if result < 0.0 {
+                        " - ".to_string()
+                    } else {
+                        " + ".to_string()
+                    },
+                    result.abs()
+                )
+            } else {
+                "".to_string()
+            }
+        }
+    )
+}
+
+fn square_string(points: &[[f64;2];3]) -> String {
+    let a = -((points[0][0] * points[1][1] - 
+            points[0][0] * points[2][1] -
+            points[1][0] * points[0][1] +
+            points[1][0] * points[2][1] +
+            points[2][0] * points[0][1] -
+            points[2][0] * points[1][1])
+            /
+            ((points[0][0] - points[1][0]) *
+            (points[0][0] - points[2][0]) *
+            (points[1][0] - points[2][0])));
+
+    let b = (points[0][0].powi(2) * points[1][1] -
+            points[0][0].powi(2) * points[2][1] -
+            points[1][0].powi(2) * points[0][1] +
+            points[1][0].powi(2) * points[2][1] +
+            points[2][0].powi(2) * points[0][1] -
+            points[2][0].powi(2) * points[1][1])
+            /
+            ((points[0][0] - points[1][0]) *
+            (points[0][0] - points[2][0]) *
+            (points[1][0] - points[2][0]));
+
+    let c = (points[0][0].powi(2) * points[1][0] * points[2][1] -
+            points[0][0].powi(2) * points[2][0] * points[1][1] -
+            points[0][0] * points[1][0].powi(2) * points[2][1] +
+            points[0][0] * points[2][0].powi(2) * points[1][1] +
+            points[1][0].powi(2) * points[2][0] * points[0][1] -
+            points[1][0] * points[2][0].powi(2) * points[0][1])
+            /
+            ((points[0][0] - points[1][0]) *
+            (points[0][0] - points[2][0]) *
+            (points[1][0] - points[2][0]));
+
+    format!(
+        "{}x^2{}{}",
+        if a == -1.0 {
+            "-".to_string()
+        } else if a != 1.0 {
+            a.to_string()
+        } else {
+            "".to_string()
+        },
+        if b != 0.0 {
+            format!(
+                "{}{}",
+                if b < 0.0 {
+                    " - ".to_string()
+                } else {
+                    " + ".to_string()
+                },
+                if b != 1.0 {
+                    format!("{}x", b.abs())
+                } else {
+                    "x".to_string()
+                }
+            )
+        } else {
+            "".to_string()
+        },
+        if c != 0.0 {
+            format!(
+                "{}{}",
+                if c < 0.0 {
+                    " - ".to_string()
+                } else {
+                    " + ".to_string()
+                },
+                c.abs()
+            )
+        } else {
+            "".to_string()
+        }
+    )
+}