started reading the book

convex_hull.cpp

@@ -0,0 +1,30 @@
+#include "bits/stdc++.h"
+using namespace std;
+
+bool left_side(pair<int, int> &a, pair<int, int> &b, pair<int, int> &x) {
+    return (b.first - a.first)*(x.second - a.second) - (b.second - a.second) * (x.first - a.first) >= 0;
+}
+
+
+vector<pair<pair<int, int>, pair<int, int>>> slow_convex_hull(vector<pair<int, int>> &input) {
+    vector<pair<pair<int, int>, pair<int, int>>> output;
+    for (int i{}; i < input.size(); i++) {
+        for (int j = i +1; j < input.size(); j++) {
+            bool valid = true;
+            for (int k{}; k < input.size(); k++) {
+                if (left_side(input[i], input[j], input[k])) {
+                    valid = false;
+                }
+            }
+            if (valid) {
+                output.emplace_back(input[i], input[j]);
+            }
+        }
+    }
+    return output;
+}
+
+int main() {
+    cout << "test";
+}
+