commit 145f25b87cd0d8a8c2b388c1b1827f22659233d7
Author: Nguyen Quy Anh <23906-nguyenquy@users.noreply.gitlab.inf.ethz.ch>
Date:   Fri Mar 13 15:37:33 2026 +0100

    Update file main.cpp

diff --git a/main.cpp b/main.cpp
new file mode 100644
index 0000000..5938fc7
--- /dev/null
+++ b/main.cpp
@@ -0,0 +1,107 @@
+#include <cfloat>
+#include <iostream>
+#include <math.h>
+
+using namespace std;
+
+struct Vector2d {
+  double x, y;
+    Vector2d(double a, double b) : x(a), y(b) {}
+      Vector2d() : x(.0), y(.0) {}
+        Vector2d operator+(Vector2d v) const { return Vector2d(v.x + x, v.y + y); }
+          Vector2d operator-(Vector2d v) const { return Vector2d(x - v.x, y - v.y); }
+            Vector2d operator-(double a) const { return Vector2d(x - a, y - a); }
+              Vector2d operator+(double a) const { return Vector2d(x + a, y + a); }
+                Vector2d operator/(double a) const { return Vector2d(x / a, y / a); }
+                  Vector2d operator*(double a) const { return Vector2d(x * a, y * a); }
+                    Vector2d operator+=(const Vector2d &v) {
+                        *this = *this + v;
+                            return *this;
+                              }
+                                double norm() { return sqrt(x * x + y * y); }
+                                  double dot(Vector2d v) { return x * v.x + y * v.y; }
+                                    void reset() {
+                                        x = 0;
+                                            y = 0;
+                                              }
+                                              };
+
+                                              // Numer of pedestrians
+                                              // $n_p$
+                                              const int n_p = 100;
+
+                                              // Number of iterations
+                                              // $n_{iter}$
+                                              const int n_iter = 100;
+
+                                              // TODO: Change this
+                                              // $\tau$
+                                              const double tau = 0.12345;
+
+                                              void compute_acceleration_term(Vector2d *F_i) {}
+                                              void compute_repulsive_effects_from_pedestrians(Vector2d *F_i) {}
+                                              void compute_repulsive_effects_from_borders(Vector2d *F_i) {}
+
+                                              // Return an array of doubles
+                                              double *w(Vector2d e, Vector2d f) {
+
+                                                // TODO:
+                                                  // $cos(60\degree)$
+                                                    // if (e * f > f.norm() * (0.5)) {
+                                                      // }
+                                                        // return 0;
+                                                        }
+
+                                                        int main() {
+
+                                                          // ! DONT TOUCH
+
+                                                            // $\vec{v}^0_i$
+                                                              // Velocity at iteration $t$ for pedestrian $i$
+                                                                double v[n_iter][n_p];
+
+                                                                  // $\vec{r}^0_i$
+                                                                    // Intended destination at iteration $t$ for pedestrian $i$
+                                                                      Vector2d r[n_iter][n_p];
+
+                                                                        // $\vec{e}_i$
+                                                                          // Desired direction to the next way point at iteration $t$ for pedestrian $i$
+                                                                            Vector2d e[n_iter][n_p];
+
+                                                                              // $v_i^{max}$
+                                                                                // Maximum allowed speed for pedestrian $i$
+                                                                                  double v_max[n_p];
+
+                                                                                    // $v_i^{0}$
+                                                                                      // Desired speed for pedestrian $i$
+                                                                                        double v_0[n_p];
+
+                                                                                          // $\vec{F}_i$
+                                                                                            // Total social force for pedestrian $i$
+                                                                                              Vector2d F[n_p][n_p];
+
+                                                                                                // $\vec{r}_0$
+                                                                                                  // Desired destination of pedestrian $n_p$
+                                                                                                    Vector2d r_0[n_p];
+
+                                                                                                      for (int t = 0; t < n_iter; t++) {
+                                                                                                          for (int i = 0; i < n_p; i++) {
+                                                                                                                for (int itr = 0; itr < n_p; itr++) {
+                                                                                                                        F[i][itr].reset();
+                                                                                                                              }
+                                                                                                                                    compute_acceleration_term(F[i]);
+                                                                                                                                          compute_repulsive_effects_from_pedestrians(F[i]);
+                                                                                                                                                compute_repulsive_effects_from_borders(F[i]);
+
+                                                                                                                                                      // TODO: Update $\vec{w}_i$
+
+                                                                                                                                                            // TODO: Update $\vec{v}_i^{t+1}$
+
+                                                                                                                                                                  // TODO: pdate $\vec{r}_i^{t+1}$
+                                                                                                                                                                      }
+                                                                                                                                                                        }
+
+                                                                                                                                                                          return 0;
+                                                                                                                                                                          }
+
+                                                                                                                                                                          
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