[C/C++ 演算法]- 蒙地卡羅法求 PI – jashliao部落格

#include 
#include 
#include 
#define N 50001

int main(void) {
srand(time(NULL));
int sum = 0;
int i;
for(i = 1; i < N; i++) {
double x = (double) rand() / RAND_MAX;
double y = (double) rand() / RAND_MAX;
if((x * x + y * y) < 1) {
sum++;
}
}
printf("PI = %f\n", (double) 4 * sum / (N - 1));
return 0;
}