hi, i need help! I have to write a program in C ++ with allegro and I don't know where to start. The exam consists of the random evolution of a black spot in the center (bodyless shape) that with the passage of time becomes bigger and gray
using namespace std;
struct cell {//defining cell
int place;
char p;
bool is_stem;
};
static const int N = 2000; //lattice size
bool lattice[N*N] = {false}; //empty lattice
vector<cell> cells; //vector containing all cells present in the system
static const int indcNeigh[] = {-N-1, -N, -N+1, -1, 1, N-1, N, N+1};//neighborhood
char pmax=10; //proliferation capacity
double pDiv=1./24.; //division probability
double alpha=0.05; //spontaneous death probability
double ps=0.05; //probability of symmetric division
double pmig=10./24.; //probability of migration
void initialize() {
for (int i=0; i<N; i++) {lattice[i]=true;};//filling left
for (int i=0; i<N*N; i=i+N) {lattice[i]=true;};//filling top
for (int i=N-1; i<N*N; i=i+N) {lattice[i]=true;};//filling bottom
for (int i=N*(N-1); i<N*N; i++) {lattice[i]=true;};//filling right
lattice[N/2*N+N/2] = true; //initial cell in the middle
cell initialCell = {N/2*N+N/2,pmax,true};//initial cell definition
cells.push_back(initialCell);
}
int returnEmptyPlace(int indx) {
int neigh[8], nF = 0;
for(int j=0;j<8;j++) {//searching through neighborhood
if (!lattice[indx+indcNeigh[j]]) {//if free spot
neigh[nF] = indx+indcNeigh[j]; //save the index
nF++; //increase the number of found free spots
}
}
if(nF) {//selecting free spot at random
return neigh[rand() % nF];
} else {//no free spot
return 0;
}
}
void simulate(int nSteps) {
vector<cell> cellsTmp;
int newSite;
cell currCell, newCell;
for (int i=0; i<nSteps; i++) {
random_shuffle(cells.begin(), cells.end()); //shuffling cells
while (!cells.empty()) {
currCell=cells.back(); //pick the cell
cells.pop_back();
newSite = returnEmptyPlace(currCell.place);
if (newSite) {//if there is a new spot
newCell = currCell;
newCell.place = newSite;
if ((double)rand()/(double)RAND_MAX < pDiv) {
if (currCell.is_stem) {
lattice[newSite]=true;
cellsTmp.push_back(currCell);
if ((double)rand()/(double)RAND_MAX > ps) {//asymmetric division
newCell.is_stem = false;
}
cellsTmp.push_back(newCell);
} else if (currCell.p > 0 && (double)rand()/(double)RAND_MAX > alpha) {
currCell.p--;
newCell.p--;
lattice[newSite] = true;
cellsTmp.push_back(currCell);
cellsTmp.push_back(newCell);
} else {
lattice[currCell.place] = false;
}
} else if ((double)rand()/(double)RAND_MAX < pmig) {
lattice[currCell.place] = false;
lattice[newSite] = true;
cellsTmp.push_back(newCell);
} else {//doing nothing
cellsTmp.push_back(currCell);
}
} else {//no free spot
cellsTmp.push_back(currCell);
}
}
cells.swap(cellsTmp);
}
}
int main() {
srand(time(NULL)); //initialize random number generator
initialize(); //initialize CA
simulate(24*30*6);
return 0;
}