亂數配合面積求π

#include<iostream.h>
#include<stdlib.h>
#include<time.h>
#define N 50000
int main(){
	int i,sum=0;
	double x,y;
	srand(time(NULL));
	for(i=1;i<N;i++){
		x=(double) rand()/RAND_MAX;
		y=(double) rand()/RAND_MAX;
		if((x*x+y*y)<1)
			sum++;
	}
	cout<<"Pi="<<(double)4*sum/N<<endl;
	return 0;
}

隨機數算法初步