UVA: 10137 Programming Challenges (Skiena & Revilla) Volume-1

UVA:10137: The Trip

Background- This problem has nothing special. It is just small implementation trick around floating point optimization that you have to disable somehow to stop the loss of mantissa. On more about problem description visit UVA:10137: The Trip.

C++ Implementation -

#include <iostream>
#include <list>
#include <iterator>
#include <numeric>
#include <cmath>
#include <functional>
#include <algorithm>
using namespace std;
unsigned long no_of_students =0;

double compute(const list<double>& data) {
    double avg = accumulate(data.begin(), data.end(), 0.0) / data.size();
    list<double>::const_iterator it = data.begin();
    double positive = 0.0;    
    double negative = 0.0;
    while(it != data.end()) {
        if(*it >= avg)
            positive += (double) (long) ((*it - avg)*100.0)/100.0;
        else
            negative += (double) (long) ((avg- *it)*100.0)/100.0;
        it++;
    }
    return max<double>(positive, negative);
}

/* main
 *  * */
int main() {
    double exchange = 0.0;
    list<double> data;    
    cin >> no_of_students;
    while(no_of_students != 0) {
        data.clear();    
        while(no_of_students-- > 0) {
            double amount;
            cin >> amount;
            data.push_back(amount);
        }
        exchange = compute(data);
        cout.precision(2);
        cout.setf(ios::fixed,ios::floatfield);
        cout << "$" << exchange << endl;
        cin >> no_of_students;
    }
    return 0;
}