C++随机数生成-优快云博客

本文介绍了使用C++标准库中的random模块来生成随机数的方法，包括整数和实数的随机分布，并通过示例展示了如何在程序中正确地初始化和使用随机数生成器。

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#include<iostream>
#include<random>
using namespace std;

/*
    default_random_engine need to be static
*/
vector<int> errorRandomFun()
{
    default_random_engine e;
    //generator random num in 0-14
    uniform_int_distribution<unsigned> u(0,15);
    vector<int> vec;
    for(int i=0;i<5;i++)
    {
        int num = u(e);
        vec.push_back(num);
        cout << num << " ";
    }
    cout << endl;

    return vec;
}

vector<int> randomFun()
{
    static default_random_engine e;
    //generator random num in 0-14
    uniform_int_distribution<unsigned> u(0,15);
    vector<int> vec;
    for(int i=0;i<5;i++)
    {
        int num = u(e);
        vec.push_back(num);
        cout << num << " ";
    }
    cout << endl;

    return vec;
}

int main()
{
    default_random_engine e;
    cout << "min:" << e.min() << ",max:" << e.max() << endl;
    for(int i=0;i<5;i++){
        cout << e() << " ";
    }
    cout << endl;

    cout << "error random function:" << endl;
    errorRandomFun();
    errorRandomFun();

    cout << "right random function:" << endl;
    randomFun();
    randomFun();
}

min:1,max:2147483646
16807 282475249 1622650073 984943658 1144108930 
error random function:
0 2 12 7 8 
0 2 12 7 8 
right random function:
0 2 12 7 8 
3 0 10 10 14


#include <random>
#include <iostream>
using namespace std;

int main()
{
	default_random_engine e;
	uniform_real_distribution<double> u(0,2);
	for(int i=0;i<5;i++)
		cout << u(e) << " ";
	cout << endl;
}

1.62945 0.270954 1.81158 1.67002 0.253974

random(new)