Euler integration again

struct IntegratorTest {  IntegratorTest() {    int count = 100;    float x = 0.f;    float v = 0.f;    float a = 9.81f;    float dt = 1.f/float(count);    int i;    printf("Euler:\n");    for (i=0; i < count; i++) {      v += a*dt;      x += v*dt;      printf("V: %f X: %f\n",v,x);    } // for    printf("Velocity-less Verlet:\n");    float xc = 0.f;    float xo = xc;    for (i=0; i < count; i++) {      v = xc - xo + a*dt*dt; // I compute velocity and store it. Useful in particle systems, collisions. Note no temp is required.      xo = xc;      xc += v;      printf("V: %f X: %f\n",v/dt,xc);    } // for    printf("Euler - Verlet\n"); // My Euler-Verlet variant.// Optimal for simple fixed time-step simulation.// Allows excellent optimizations and improves overall code quality.    x = v = 0.f;    for (i=0; i < count; i++) {      v += a*dt*dt;      x += v;      printf("V: %f X: %f\n",v/dt,x);    } // for  }} test;

// My Euler-Verlet variant.// Optimal for simple fixed time-step simulation.// Allows excellent optimizations and improves overall code quality.  x = v = 0.f;  for (i=0; i < count; i++) {    v += a*dt*dt;    x += v;    printf("V: %f X: %f\n",v/dt,x);  } // for