I2DOA - Lab0 - Ex14

#include <iostream>
#include <cstdlib>
#include <map>
#include <cmath>

using namespace std;
#define RUNS 2000
#define PI 3.141592653589793238463

struct calculation
{
    int matched;
    int total;
};

double makerand()
{
    return (double)rand() / RAND_MAX;
}

double getPi(int matched, int total)
{
    return 4*(double)matched / total;
}

bool checkGoodPrescision(int matched, int total,int prec)
{
    return floor(getPi(matched,total)*pow(10,prec)) == floor(PI*pow(10,prec));
}

int main()
{
    int matched = 0;
    int total = 0;
    //int prec = 1;
    map<int,calculation> prescitions;

    for(short prec = 1; prec < 10; ++prec)
    {
        //cout << "Prescition is set to " << prec << " decimals" << endl;
        //cout << "Starting calculations"<< endl;
        while(!checkGoodPrescision(matched,total,prec))
        {
            //Loop a few times before we check
            short toSkip = log(total+1)+1;
            for(int i = 0; i < toSkip;++i)
            {
                //if(sqrt(2) * sqrt( pow(makerand(),2) ) <=1)
                if(sqrt( pow(makerand(),2) + pow(makerand(),2) ) <=1)
                    ++matched;
                ++total;
            }

            //cout << "\tCurrent iterations: " << total << " pi: " << getPi(matched,total) << endl;
        }

        calculation calc;
        calc.matched = matched;
        calc.total = total;
        prescitions[prec] = calc;

        cout << "###### RESULTS ######" << endl;
        for(auto prec = prescitions.begin(); prec != prescitions.end();++prec)
        {
            cout << "Prescition: " << (*prec).first << endl;
            cout << "\tPi was found to be: " << getPi((*prec).second.matched,(*prec).second.total) << endl;
            cout << "\tIt took " << (*prec).second.total << " iterations. " << (*prec).second.matched << " of them matched" << endl;
        }
    }

    return 0;
}

//RESULTS
Prescition: 1
        Pi was found to be: 3.16667
        It took 24 iterations. 19 of them matched
Prescition: 2
        Pi was found to be: 3.14504
        It took 131 iterations. 103 of them matched
Prescition: 3
        Pi was found to be: 3.1411
        It took 163 iterations. 128 of them matched
Prescition: 4
        Pi was found to be: 3.1415
        It took 329683 iterations. 258925 of them matched
Prescition: 5
        Pi was found to be: 3.1416
        It took 329891 iterations. 259096 of them matched
Prescition: 6
        Pi was found to be: 3.14159
        It took 329904 iterations. 259106 of them matched
Prescition: 7
        Pi was found to be: 3.14159
        It took 353161 iterations. 277372 of them matched