#include #include using namespace std; // Iterations for Euler's method const int DAYS = 200, ITER = 10000; // Population size const int POP = 10000; // Model parameters // Beta = infection rate // Gamma = removal rate const double beta = 0.3944, gamma = 0.02664; // Compartments double S[DAYS + 1], I[DAYS + 1], R[DAYS + 1]; int main() { // Initial conditions S[0] = 1 - 1.0 / POP, I[0] = 1.0 / POP, R[0] = 0; // Run simulation for (int i = 0; i < DAYS; ++i) { double S_[ITER + 1], I_[ITER + 1], R_[ITER + 1]; S_[0] = S[i], I_[0] = I[i], R_[0] = R[i]; // Euler's method for (int j = 0; j < ITER; ++j) { S_[j+1] = S_[j] + (-beta * S_[j] * I_[j]) / ITER; I_[j+1] = I_[j] + (beta * S_[j] * I_[j] - gamma * I_[j]) / ITER; R_[j+1] = R_[j] + (gamma * I_[j]) / ITER; } S[i + 1] = S_[ITER], I[i + 1] = I_[ITER], R[i + 1] = R_[ITER]; } // Print results cout << "| DAY | SUSCEPTIBLE | INFECTIOUS | RECOVERED |\n"; cout << "-------------------------------------------------\n"; for (int i = 0; i < DAYS; ++i) { cout << "| " << setw(3) << i << " | "; // Day cout << setw(11) << (int)(POP * S[i] + .5) << " | "; // Suspectible cout << setw(11) << (int)(POP * I[i] + .5) << " | "; // Infectious cout << setw(11) << (int)(POP * R[i] + .5) << " |\n"; // Recovered } }