/* montecarlo approximation of pi in c */
#include <stdio.h>
#include <time.h>
#include <stdlib.h>
#include <math.h>

#define ITERATIONS 100000000

int in_circle(float x, float y) {
    if (sqrt(x*x + y*y) <= 1.0) {
        return 1;
    }
    return 0;
}

int main() {
    srand(time(NULL));
    rand();

    int hits=0;

    for (int i=0; i<ITERATIONS; i++) {
        float r1 = (float)rand()/(float)RAND_MAX;
        float r2 = (float)rand()/(float)RAND_MAX;
        if (in_circle(r1, r2)) {
            hits++;
        }
    }
    printf("Pi: %0.6f\n", (4 * ((float)hits / ITERATIONS)));
    return 0;
}