static void gogo_ant(ref ant_t ant, matrix_t adj_mat, matrix_t weight, matrix_t d_pheromon, int q)
{
int N = weight.n;
int i = 1;
int next = 0;
array_t prob = create_array(N);
while (i < N)
{
double sum_weight = 0;
for (int j = 0; j < N; j++)
{
sum_weight += weight.matr[ant.curr_city, j] * ant.Jk.arr[j];
}
for (int j = 0; j < N; j++)
{
prob.arr[j] = weight.matr[ant.curr_city, j] / sum_weight * ant.Jk.arr[j];
}
next = choose_next(prob);
ant.curr_city = next;
ant.Jk.arr[next] = 0;
ant.route.arr[i++] = next;
}
ant.Lk = (int)(length_of_route(adj_mat, ant.route));
add_pheromon(d_pheromon, ant.route, ant.Lk, q);
}
static array_t create_array(int size)
{
array_t array = new array_t();
array.arr = new double[size];
array.size = size;
return(array);
}
static void add_pheromon(matrix_t d_pheromon, array_t route, int Lk, int q)
{
float d_fer = (float)q / (float)Lk;
for (int i = 0; i < route.size - 1; i++)
{
d_pheromon.matr[(int)route.arr[i], (int)route.arr[i + 1]] += d_fer;
}
}
static void copy_array(array_t dst, array_t src)
{
if (dst.size == src.size)
{
for (int i = 0; i < dst.size; i++)
{
dst.arr[i] = src.arr[i];
}
}
}
static double length_of_route(matrix_t adj_mat, array_t route)
{
double length = 0;
for (int i = 0; i < route.size - 1; i++)
{
length += adj_mat.matr[(int)route.arr[i], (int)route.arr[i + 1]];
}
return(length);
}
static int choose_next(array_t prob)
{
int i = 0;
double r = rand.NextDouble();
if (r == 0)
{
while (prob.arr[i++] <= 0)
{
;
}
return(--i);
}
while (r > 0)
{
r -= prob.arr[i++];
}
return(--i);
}
static solution_t solve(matrix_t adj_mat, double a, double b, double p, int q, int t_max)
{
int N = adj_mat.n;
ant_t[] ants = create_ant_array(N);
matrix_t pheromon = create_matrix(N, N);
for (int i = 0; i < N; i++)
{
for (int j = 0; j < N; j++)
{
pheromon.matr[i, j] = 0.5;
}
}
matrix_t visib = create_matrix(N, N);
for (int i = 0; i < N; i++)
{
for (int j = i; j < N; j++)
{
if (i != j)
{
visib.matr[i, j] = 1 / adj_mat.matr[i, j];
visib.matr[j, i] = visib.matr[i, j];
}
else
{
visib.matr[i, j] = 1000;
}
}
}
matrix_t weight = create_matrix(N, N);
recalc_weight(ref weight, pheromon, visib, a, b);
int best_l = int.MaxValue;
array_t route = create_array(N);
for (int t = 0; t < t_max; t++)
{
for (int k = 0; k < N; k++)
{
init_ant(ref ants[k]);
gogo_ant(ref ants[k], adj_mat, weight, pheromon, q);
}
int best = -1;
for (int i = 0; i < N; i++)
{
if (ants[i].Lk < best_l)
{
best = i;
best_l = ants[i].Lk;
}
}
if (best != -1)
{
copy_array(route, ants[best].route);
}
recalc_pheromon(ref pheromon, p);
recalc_weight(ref weight, pheromon, visib, a, b);
}
solution_t solv = new solution_t();
solv.l = best_l;
solv.route = route;
return(solv);
}
