这里有一个解决方案。创建一个返回随机数的函数并放置它 在main函数之外，使其具有全局性。希望这能有所帮助

#include <iostream>
#include <cstdlib>
#include <ctime>
int rollDie();
using std::cout;
int main (){
    srand((unsigned)time(0));
    int die1;
    int die2;
    for (int n=10; n>0; n--){
    die1 = rollDie();
    die2 = rollDie();
    cout << die1 << " + " << die2 << " = " << die1 + die2 << "\n";
}
system("pause");
return 0;
}
int rollDie(){
    return (rand()%6)+1;
}

#include <iostream>
#include <cstdlib>
#include <ctime>

int main() {
    srand(time(NULL));
    int random_number = std::rand(); // rand() return a number between ​0​ and RAND_MAX
    std::cout << random_number;
    return 0;
}

http://en.cppreference.com/w/cpp/numeric/random/rand

这是一个简单的随机生成器。在0附近产生正负值的概率相等:

  int getNextRandom(const size_t lim) 
  {
        int nextRand = rand() % lim;
        int nextSign = rand() % lim;
        if (nextSign < lim / 2)
            return -nextRand;
        return nextRand;
  }


   int main()
   {
        srand(time(NULL));
        int r = getNextRandom(100);
        cout << r << endl;
        return 0;
   }

以下是我的5美分:

// System includes
#include <iostream>
#include <algorithm>
#include <chrono>
#include <random>

// Application includes

// Namespace
using namespace std;

// Constants
#define A_UNUSED(inVariable) (void)inVariable;


int main(int inCounter, char* inArguments[]) {

    A_UNUSED(inCounter);
    A_UNUSED(inArguments);

    std::random_device oRandomDevice;
    mt19937_64 oNumber;
    std::mt19937_64::result_type oSeed;
    std::mt19937_64::result_type oValue1;
    std::mt19937_64::result_type oValue2;

    for (int i = 0; i < 20; i++) {

        oValue1 = (std::mt19937_64::result_type) std::chrono::duration_cast<std::chrono::seconds>(
            std::chrono::system_clock::now().time_since_epoch()
        ).count();
        oValue2 = (std::mt19937_64::result_type) std::chrono::duration_cast<std::chrono::microseconds>(
            std::chrono::system_clock::now().time_since_epoch()
        ).count();
        oSeed = oRandomDevice() ^ (oValue1 + oValue2);
        oNumber.seed(oSeed);

        cout << "oNumber: " << oNumber << "\n";
        cout << "oNumber.default_seed: " << oNumber.default_seed << "\n";
        cout << "oNumber.initialization_multiplier: " << oNumber.initialization_multiplier << "\n";
        cout << "oNumber.mask_bits: " << oNumber.mask_bits << "\n";
        cout << "oNumber.max(): " << oNumber.max() << "\n";
        cout << "oNumber.min(): " << oNumber.min() << "\n";
        cout << "oNumber.shift_size: " << oNumber.shift_size << "\n";
        cout << "oNumber.state_size: " << oNumber.state_size << "\n";
        cout << "oNumber.tempering_b: " << oNumber.tempering_b << "\n";
        cout << "oNumber.tempering_c: " << oNumber.tempering_c << "\n";
        cout << "oNumber.tempering_d: " << oNumber.tempering_d << "\n";
        cout << "oNumber.tempering_l: " << oNumber.tempering_l << "\n";
        cout << "oNumber.tempering_s: " << oNumber.tempering_s << "\n";
        cout << "oNumber.tempering_t: " << oNumber.tempering_t << "\n";
        cout << "oNumber.tempering_u: " << oNumber.tempering_u << "\n";
        cout << "oNumber.word_size: " << oNumber.word_size << "\n";
        cout << "oNumber.xor_mask: " << oNumber.xor_mask << "\n";
        cout << "oNumber._Max: " << oNumber._Max << "\n";
        cout << "oNumber._Min: " << oNumber._Min << "\n";
    }

    cout << "Random v2" << endl;
    return 0;
}

非常固执己见的回答

c++ <random>库违反了软件工程的最佳原则之一:“简单的事情做简单，复杂的事情，不寻常的事情可以更复杂一点。”

相反，他们甚至把简单和常见的用例变得过于复杂，只是因为他们患有文化疾病，害怕像“这还不够普遍”这样的评论。

As a result, now whenever you want a simple random number, you have to look into the documentation, read stack overflow with walls of text, glorifying this terrible design, instead of it just being an easy-to-remember one or 2 liner. (Common Lisp is more pragmatic: (random 5) yields uniformly distributed integers from 0..4 and (random 1.0) yields real numbers between 0.0..1.0. That is the most common use case and it is at your finger tips. If you need more sophisticated stuff, you have to find packages and libraries or do it yourself.)

只需计算一下全球范围内每个人浪费在理解标题及其内容上的时间累积的工时，就可以看到它有多糟糕。

即使我现在在浪费我的时间，写这个答案，你也在浪费时间，阅读它，只是因为他们创造了一个复杂的谜题，这与其他现代令人厌恶的东西相似，比如Vulkan API。

那么，如何应对呢?浪费一次时间，为自己最常见的用例编写一个头文件，然后在需要时重用它。

这里有一个解决方案。创建一个返回随机数的函数并放置它 在main函数之外，使其具有全局性。希望这能有所帮助

#include <iostream>
#include <cstdlib>
#include <ctime>
int rollDie();
using std::cout;
int main (){
    srand((unsigned)time(0));
    int die1;
    int die2;
    for (int n=10; n>0; n--){
    die1 = rollDie();
    die2 = rollDie();
    cout << die1 << " + " << die2 << " = " << die1 + die2 << "\n";
}
system("pause");
return 0;
}
int rollDie(){
    return (rand()%6)+1;
}