From ff00c4ecb69ef574bb0a19c0bcfe730bd92408ea Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Gustav=20S=C3=B6rn=C3=A4s?= <gustav@sornas.net>
Date: Tue, 15 Dec 2020 13:32:30 +0100
Subject: e8 comments

---
 labb7/src/fast.cpp | 40 ++++++++++++++++++++++++----------------
 1 file changed, 24 insertions(+), 16 deletions(-)

(limited to 'labb7/src/fast.cpp')

diff --git a/labb7/src/fast.cpp b/labb7/src/fast.cpp
index e01af2d..edce769 100644
--- a/labb7/src/fast.cpp
+++ b/labb7/src/fast.cpp
@@ -30,6 +30,7 @@ void render_line(QGraphicsScene* scene, const Point& p1, const Point& p2) {
 template <typename T>
 bool vec_contains_vec(const vector<T>& v1, const vector<T>& v2) {
     if (v2.size() == 0) {
+        // every vector contains the empty vector
         return true;
     }
     int i1 = 0;
@@ -49,7 +50,7 @@ bool vec_contains_vec(const vector<T>& v1, const vector<T>& v2) {
 }
 
 /*
- * Return whether inner is contained in some vector before itself in outer.
+ * Return whether some vector is contained in some other vector before itself.
  */
 template <typename T>
 bool contained_in_before(const vector<vector<T>>& outer, int index) {
@@ -100,8 +101,9 @@ int main(int argc, char *argv[]) {
     auto begin = chrono::high_resolution_clock::now();
 
     // these contain indexes since points can't be compared
-    vector<vector<int>> lines;  // all lines we want to draw
-    vector<pair<double, int>> angles;  // for each point, the angle to every other point
+    // find the corresponding point with points.at(int)
+    vector<vector<int>> lines;
+    vector<pair<double, int>> angles;
 
     for (int p1 = 0; p1 < N-1; p1++) {
         angles.clear();
@@ -114,8 +116,10 @@ int main(int argc, char *argv[]) {
         for (int i = 2; i < angles.size(); i++) {
             double prev_angle = angles[i - 1].first;
             if (angles[i].first == prev_angle) {
+                // start of potential line
                 line.push_back(angles[i].second);
             } else {
+                // end of potential line
                 if (line.size() >= 4) {
                     lines.push_back(line);
                 }
@@ -131,7 +135,7 @@ int main(int argc, char *argv[]) {
 
     for (int i = 0; i < lines.size();) {
         if (contained_in_before(lines, i)) {
-            lines.erase(lines.begin() + i);
+            lines.erase(lines.begin() + i); //NOTE should check before inserting instead
         } else {
             i++;
         }
@@ -142,24 +146,28 @@ int main(int argc, char *argv[]) {
     }
     cout << lines.size() << " draws" << endl;
 
+    auto end = chrono::high_resolution_clock::now();
+    cout << "Computing line segments took "
+         << std::chrono::duration_cast<chrono::milliseconds>(end - begin).count()
+         << " milliseconds." << endl;
+
+    ///////////
+    // tests //
+    ///////////
+
     vector<int> v1 = {1, 2, 3};
     vector<int> v2 = {2, 3};
     vector<int> v3 = {3};
     vector<int> v4 = {2, 3, 4};
-    cout << vec_contains_vec(v1, v2) << " "
-         << vec_contains_vec(v2, v1) << " "
-         << vec_contains_vec(v1, v3) << " "
-         << vec_contains_vec(v1, v4) << endl;
+    cout << vec_contains_vec(v1, v2) << " "   // expect true
+         << vec_contains_vec(v2, v1) << " "   // expect false
+         << vec_contains_vec(v1, v3) << " "   // expect true
+         << vec_contains_vec(v1, v4) << endl; // expect false
 
     vector<vector<int>> outer = {{1,2,3}, {2,3}, {3,4}};
-    cout << contained_in_before(outer, 0) << " "
-         << contained_in_before(outer, 1) << " "
-         << contained_in_before(outer, 2) << endl;
-
-    auto end = chrono::high_resolution_clock::now();
-    cout << "Computing line segments took "
-         << std::chrono::duration_cast<chrono::milliseconds>(end - begin).count()
-         << " milliseconds." << endl;
+    cout << contained_in_before(outer, 0) << " "   // expect false
+         << contained_in_before(outer, 1) << " "   // expect true
+         << contained_in_before(outer, 2) << endl; // expect false
 
     view->show();
     return a.exec(); // start Qt event loop
-- 
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