Update graham_scan_functions.hpp

geometry/graham_scan_functions.hpp

@@ -23,15 +23,15 @@
  * are sorted, they form a simple closed path.
  * The sorting criteria is to use the orientation to compare angles without
  * actually computing them (See the compare() function below) because
- *computation of actual angles would be inefficient since trigonometric
- *functions are not simple to evaluate.
+ * computation of actual angles would be inefficient since trigonometric
+ * functions are not simple to evaluate.
  *
  * Accept or Reject Points
  * Once we have the closed path, the next step is to traverse the path and
  * remove concave points on this path using orientation. The first two points in
  * sorted array are always part of Convex Hull. For remaining points, we keep
  * track of recent three points, and find the angle formed by them. Let the
- *three points be prev(p), curr(c) and next(n). If orientation of these points
+ * three points be prev(p), curr(c) and next(n). If orientation of these points
  * (considering them in same order) is not counterclockwise, we discard c,
  * otherwise we keep it.
  *
@@ -177,29 +177,6 @@ std::vector<Point> convexHull(std::vector<Point> points, uint64_t size) {
         return {};
     };
 
-    // Create an empty stack and push first three points to it.
-    std::stack<Point> S;
-    S.push(points[0]);
-    S.push(points[1]);
-    S.push(points[2]);
-
-    // Process remaining n-3 points
-    for (int i = 3; i < m; i++) {
-        // Keep removing top while the angle formed by
-        // points next-to-top, top, and points[i] makes
-        // a non-left turn
-        while (S.size() > 1 &&
-               orientation(nextToTop(&S), S.top(), points[i]) != 2) {
-            S.pop();
-        }
-        S.push(points[i]);
-    }
-    // If modified array of points has less than 3 points, convex hull is not
-    // possible
-    if (m < 3) {
-        return {};
-    };
-
     // Create an empty stack and push first three points to it.
     std::stack<Point> St;
     St.push(points[0]);