example03.cpp

Code

/*
    example03.cpp
    Dave Klick
    CIS 250
    2011-05-21
    
    Demonstration of classes, heapsort, vector, and file input.
*/
#include <iostream>
#include <fstream>
#include <string>
#include <vector>
using std::cin;
using std::cout;
using std::ifstream;
using std::vector;
using std::string;

class Part {
    string partNumber;
    int qty;
    double cost;
public:
    Part(string sku, int quantity, double cost) {
        partNumber = sku;
        qty = quantity;
        this->cost = cost;
    }
    double getTotalCost() {
        return qty * cost;
    }
    string toString() {
        // formats Part as: sku: qty * cost = total
        //    xxxxxx: ##### * #####.## = ######.##
        char* pStr = new char[200];
        sprintf(pStr, "%6s: %5d * %8.2f = %9.2f",
            partNumber.c_str(), qty, cost, getTotalCost());
        string s(pStr);
        return s;
    }
    int compareTo(Part& p) {
        if (partNumber > p.partNumber) return 1;
        if (partNumber < p.partNumber) return -1;
        return 0;
    }
};

void siftDown(vector<Part>& parts, int k, int bottom) {
    Part tmp = parts[k-1];
    while (k <= bottom/2) {
        int j = k + k;
        if ((j < bottom) && (parts[j-1].compareTo(parts[j])<0)) j++;
        if (tmp.compareTo(parts[j-1]) >= 0) break;
        else {
            parts[k-1] = parts[j-1];
            k = j;
        }
    }
    parts[k-1] = tmp;
}

void heapSort(vector<Part>& parts) {
    int len = parts.size();
    for (int i=len/2; i>0; i--) siftDown(parts, i, len);
    do {
        Part tmp = parts[0];
        parts[0] = parts[len-1];
        parts[len-1] = tmp;
        len--;
        siftDown(parts, 1, len);
    } while (len>1);
}

void cont() {
    if (cin.rdbuf()->sungetc() != -1 && cin.get() != '\n') cin.ignore(80,'\n');
    cout << "Press enter to continue...";
    cin.get();
}

int main() {
    vector<Part> vect;
    int i;
    string strPartNum, strQty, strCost;

    ifstream infile("parts.txt");
    if (!infile) {
        cout << "Error opening file\n";
        return 1;
    }
    
    while (getline(infile, strPartNum, '|')) {
        getline(infile, strQty, '|');
        getline(infile, strCost, '\n');
        Part part(strPartNum, atoi(strQty.c_str()), atof(strCost.c_str()));
        vect.push_back(part);
    }
    infile.close();

    heapSort(vect);
    for (i=0; i<vect.size(); i++) cout << vect[i].toString() << '\n';
    
    cont();
    return 0;
}