#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#define N 10000
int main(void)
{
int i;
int count = 0;
for (i = 0; i < N; ++i) {
double x = rand() / (double)RAND_MAX;
double y = rand() / (double)RAND_MAX;
double z = rand() / (double)RAND_MAX;
if (x * x + y * y < (1 - z) * (1 - z)) {
count++;
}
}
printf("近似値:%f\n", count / (double)N);
printf("理論値:%f\n", M_PI / 12);
return 0;
}