C++随机数生成器

一个随机数生成的C++程序，参考"Data Structures and Algorithm Analysis in C++ 3th"。

 

头文件：

 

#ifndef RANDOM_H#define RANDOM_Hclass Random{public: explicit Random( int initValue=1 ); void seed( int value ); int random(); int random( int low, int high ); double random( double low, double high );private: int state;};#endif 

实现文件：

 

#include "random.h"static const int A = 48271;static const int M = 2147483647;static const int Q = 44488;static const int R = 3399;/** * Construct with initialValue for the state. */Random::Random( int initValue ){ if( initValue < 0 ) initValue += M; state = initValue; if( state == 0 ) state = 1;}/** * Set the internal state. */void Random::seed( int value ){ state = value;}/** * Return a pseudorandom int, and then change the internal state. */int Random::random(){ int tmpState = A*( state%Q ) - R*( state/Q ); if( tmpState >= 0 ) state = tmpState; else state = tmpState + M; return state;}/** * Return an int in the closed range [low, high], and * then change the internal state. */int Random::random( int low, int high ){ double normalization = random() / double(M); return (int) ( low + normalization*(high-low) );}/** * Return a pseudorandom double in the open range (low, high), * and then change the internal state. */double Random::random( double low, double high ){ double normalization = random() / double(M); return (double) ( low + normalization*(high-low) );} 

测试文件：

 

#include <iostream>#include "random.h"using namespace std;int main(){ Random rand; for( int i=0; i<10; ++i ) cout << rand.random() << "/t"; cout << endl << endl; rand.seed( 127 ); for( int i=0; i<10; ++i ) cout << rand.random( 0, 10 ) << "/t"; cout << endl << endl; rand.seed( 2011 ); for( int i=0; i<10; ++i ) cout << rand.random( 0.0, 1.0 ) << "/t"; cout << endl << endl; return 0;}