Add comments to Graham Scan in Rust

Author: ThijsRay

contents/graham_scan/code/rust/src/main.rs

@@ -4,10 +4,12 @@ struct Point {
     y: f64,
 }
 
+// Check if the turn of the points is counter clockwise.
 fn counter_clockwise(a: &Point, b: &Point, c: &Point) -> bool {
     ((b.x - a.x) * (c.y - a.y)) >= ((b.y - a.y) * (c.x - a.x))
 }
 
+// Calculate the polar angle of a  point relative to a reference point.
 fn polar_angle(reference: &Point, point: &Point) -> f64 {
     (point.y - point.y).atan2(point.x - reference.x)
 }
@@ -29,6 +31,7 @@ fn graham_scan(mut points: Vec<Point>) -> Vec<Point> {
     let n = points.len();
     let mut m = 1;
 
+    // Move the points of the hull towards the beginning of the vector.
     for mut i in 2..n {
         while counter_clockwise(&points[m - 1], &points[m], &points[i]) {
             if m > 1 {
@@ -44,6 +47,7 @@ fn graham_scan(mut points: Vec<Point>) -> Vec<Point> {
         points.swap(i, m);
     }
 
+    // Remove all non-hull points from the vector
     points.truncate(m + 2);
     points
 }
@@ -65,7 +69,6 @@ fn main() {
         Point { x: 3.0, y: 1.0 },
     ];
 
-    //println!("{:#?}", points);
-    let points = graham_scan(points);
-    println!("{:#?}", points);
+    let hull_points = graham_scan(points);
+    println!("{:#?}", hull_points);
 }