#include <stdio.h>
#include <math.h>
#include <time.h>

#define ITERATIONS 1000000
#define BENCHMARKS 20

double leibniz(int iter) {
  double n = 1.0;
  for (int i = 2; i <= iter - 1; i++) {
    n += pow(-1.0, i - 1.0) / (i * 2.0 - 1.0);
  }
  return n * 4.0;
}

int main() {
    double result;
    double total_time = 0;
    clock_t begin, end;
    for (int i = 0; i < BENCHMARKS; i++) {
        begin = clock();
        result = leibniz(ITERATIONS);
        end = clock();
        total_time += (double)(end - begin);
    }

    printf("%8lf\n", result);
    printf("Avg execution time: %8lf\n", total_time / BENCHMARKS / CLOCKS_PER_SEC);
}