#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <iostream>
#include <omp.h>
#include <list>
#include <math.h>

using namespace std;

//INTEGRAL DATA
long step_count = 100000000;
double a = 0;
double b = 1;
double dx = (b-a)/step_count;

//MONTE CARLO DATA
long point_count = 10000000;

double function(double x){
    return 1/(1+(x*x));
}

struct Point{
    double a;
    double b;

    Point() { }
    Point(double a_, double b_) : a(a_), b(b_) { }
};

void zad1(){
  double normal_sum = 0;
  for (long i=0; i<step_count; i++){
      normal_sum += function(a+i*dx) * dx;
  }
  cout << "Integral PI resoult: " << 4 * normal_sum << endl;
}

void zad2(){
  double parallel_sum[128];
  for (int i=0; i < 128; i++){
      parallel_sum[i] = 0;
  }

  #pragma omp parallel
  {
      double sum = 0;
      for (long i=omp_get_thread_num(); i<step_count; i += omp_get_num_threads()){
          sum += function(a+i*dx) * dx;
      }
      parallel_sum[omp_get_thread_num()] = sum;
  }

  double sum = 0;
  for (int i=0; i < 128; i++){
      sum += parallel_sum[i];
  }
  cout << "Parallel integral PI resoult: " << 4 * sum << endl;
}

void zad3(){
  double parallel_sum = 0;
  #pragma omp parallel for reduction(+:parallel_sum)
  for (long i=0; i<step_count; i++){
      parallel_sum += function(a+i*dx) * dx;
  }
  cout << "For reduction integral PI resoult: " << 4 * parallel_sum << endl;
}

void zad4(){
  long insideCircle = 0;
  for (long i=0; i<point_count; i++){
      Point point = Point(((double) rand() / (RAND_MAX)), ((double) rand() / (RAND_MAX)));
      //środek okręgu S = (0,0), r = 1;
      // (a - Sx)^2 + (b- Sy)^2 < r^2
      if(pow(point.a,2.0) + pow(point.b,2.0) < 1){
        insideCircle ++;
      }
  }
  cout << "Monte Carlo PI resoult: " << double(4*insideCircle) / double(point_count) << endl;

}

void zad5(){
  int parallel_insideCircle[128];
  for (int i=0; i < 128; i++){
      parallel_insideCircle[i] = 0;
  }

  #pragma omp parallel
  {
      int insideCircle = 0;
      for (long i=0; i<point_count/omp_get_num_threads(); i++){
          Point point = Point(((double) rand() / (RAND_MAX)), ((double) rand() / (RAND_MAX)));
          if(pow(point.a,2.0) + pow(point.b,2.0) < 1){
            insideCircle ++;
          }
      }
      parallel_insideCircle[omp_get_thread_num()] = insideCircle;
  }

  int insideCircle = 0;
  for (int i=0; i < 128; i++){
      insideCircle += parallel_insideCircle[i];
  }
  cout << "Parallel Monte Carlo PI resoult: " << double(4*insideCircle) / double(point_count) << endl;
}


void zad6(){
  int parallel_insideCircle = 0;

  #pragma omp parallel for reduction(+:parallel_insideCircle)
  for (long i=0; i<point_count; i++){
    Point point = Point(((double) rand() / (RAND_MAX)), ((double) rand() / (RAND_MAX)));
    if(pow(point.a,2.0) + pow(point.b,2.0) < 1){
      parallel_insideCircle ++;
    }
  }

  cout << "For reduction Monte Carlo PI resoult: " << double(4*parallel_insideCircle) / double(point_count) << endl;
}

int main() {
    zad1();
    zad2();
    zad3();
    zad4();
    zad5();
    zad6();
}