MCA.rar_MCA_模拟 π

#include <stdio.h> #include <stdlib.h> #include <time.h> #include <math.h> #include <iostream> using namespace std; ///////////////////////// 蒙特卡罗算法 Monte Carlo Algorithm MCA 解决 pi 问题 by hsluoyz //////////////////////////////////// struct Sample{ //sample part double x; double y; //sample part }; int sum; int got; Sample smp; double ObjectiveFunction(Sample asmp){ //object part if (asmp.x * asmp.x + asmp.y * asmp.y <= 1) return 1; else return 0; //object part } int RandomIntLessThan(int aint){ return (int) ((double) aint * (double) rand() / (double) (RAND_MAX + 1)); } double RandomDoubleLessThan(double adouble){ return adouble * (double) rand() / (double) (RAND_MAX); } int RandomTrueBy(double aprob){ double res = (double) rand() / (RAND_MAX + 1); if (res <= aprob) return 1; else return 0; } Sample GenSmp(){ //sample part Sample res; res.x = RandomDoubleLessThan(2) - 1; res.y = RandomDoubleLessThan(2) - 1; //cout << res.x << " " << res.y << endl; return res; //sample part } void main(){ srand((unsigned) time(NULL)); sum = 10000000; got = 0; for (int i = 0; i < sum; i ++){ smp = GenSmp(); if (ObjectiveFunction(smp)) got ++; } //object part cout << "The pi is " << 4 * (double) got / (double) sum << endl; //object part }