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#include <iostream>
#include <fstream>
#include <cstdlib>
#include <string>
using namespace std;
// point object structure
struct point {
double x, y;
void p_str() {
cout << "(" << x << ", " << y << ")" << endl;
}
};
// declaration of method
void readPoints(string, int&, int&, point*&);
int main() {
string fileLocation = "./PointFile.txt";
// declares the size and capacity of the array which both have to be tracked and initialises them
int size = 0;
int capacity = 1;
point* pArray = new point[capacity];
readPoints(fileLocation, capacity, size, pArray);
// prints out the content of the array
for(int i = 0; i < size; i++) {
pArray[i].p_str();
}
// prints out the characteristics of the array
cout << "array capacity:\t\t" << capacity << endl << "array size:\t\t" << size << endl << "array physical size:\t" << size*sizeof(point) << " bits\t=\t" << size*sizeof(point)/8 << " bytes" << endl;
delete[] pArray;
return 0;
}
// method that creates the array
void readPoints(string fileloc, int &cpcty, int &sz, point* &pa) {
// declares file and other variables
ifstream pointFile;
point tmpp;
pointFile.open(fileloc);
// Error opening file
if(!pointFile.is_open()) {
cout << "couldn't open input file" << endl;
exit(EXIT_FAILURE);
}
// reads the two points from the file
while(pointFile >> tmpp.x >> tmpp.y) {
// increases the sz of the array
sz++;
// checks if the array is still large enough for the element
if(sz <= cpcty) {
// adds point to the end of the array
pa[sz-1] = tmpp;
} else {
// if array isn't large enough creates new dynamic array
// of two times the sz
point* tmpa = new point[cpcty*=2];
for(int i = 0; i < sz; i++) {
tmpa[i] = pa[i];
}
// never have to delete the tmpa as it points to the new pa
tmpa[sz-1] = tmpp;
// delete old pa
delete[] pa;
pa = tmpa;
}
}
pointFile.close();
}
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