Generering af tilfældige tal er et almindeligt krav i mange programmeringsapplikationer, og C++ giver flere måder at generere tilfældige tal inden for et givet område. I denne artikel vil vi udforske forskellige metoder til at generere tilfældige tal mellem 1 og 10 i C++.
Metode 1:
Brug af rand() funktion:
En af de enkleste metoder til at generere et tilfældigt tal mellem 1 og 10 i C++ er rand() fungere. Denne funktion er defineret i header-fil og genererer et tilfældigt heltal inden for et interval på 0 til RAND_MAX . Værdien af RAND_MAX er implementeringsafhængig og kan variere fra compiler til compiler.
Eksempel:
Lad os tage et eksempel for at generere et tilfældigt tal mellem 1 og 10 ved hjælp af rand()-funktionen, vi kan bruge følgende kode:
#include #include #include using namespace std; int main() { srand(time(0)); cout<< 'Random number between 1 and 10 is: '<<endl; for(int i="0;i<10;i++)" cout << (rand() % 10) + 1<<' '; return 0; } < pre> <p> <strong>Output</strong> </p> <pre> Random number between 1 and 10 is: 4 5 7 10 7 5 1 7 10 2 </pre> <p>In this code, we have included the <strong> <em></em> </strong> and <strong> <em></em> </strong> header files. The <strong> <em>srand()</em> </strong> function is used to initialize the random number generator with the current time as the seed. It ensures that every time the program is run, a new sequence of random numbers is generated.</p> <p>The <strong> <em>rand()</em> </strong> function is used to generate a random integer between 0 and <strong> <em>RAND_MAX</em> </strong> . To limit the range between 1 and 10, we take the remainder of this number when divided by 10 and add 1 to it.</p> <h3>Method 2:</h3> <p> <strong>Using C++11 random library</strong> </p> <p>The <strong> <em>C++11</em> </strong> standard introduced a new library called <strong> <em></em> </strong> that provides a better way to generate random numbers. This library provides several random number generation engines and distributions that can generate random numbers with a uniform distribution.</p> <p> <strong>Example:</strong> </p> <p>Let's take an example to generate a random number between 1 and 10 using the <strong> <em></em> </strong> library, we can use the following code:</p> <pre> #include #include using namespace std; int main() { random_device rand; mt19937 gen(rand()); uniform_int_distributiondis(1, 10); int random_number = dis(gen); cout<< 'Random number between 1 and 10 is: ' <<random_number<<endl; return 0; } < pre> <p>In this code, we have included the <strong> <em></em> </strong> header file. The <strong> <em>random_device</em> </strong> class is used to obtain a seed value for the random number generator. The <strong> <em>mt19937</em> </strong> class is a random number generation engine that produces random numbers with a uniform distribution. The <strong> <em>uniform_int_distribution</em> </strong> class is used to generate random integers within a given range.</p> <p>By default, the <strong> <em>mt19937</em> </strong> engine uses a seed value of <strong> <em>5489</em> </strong> , which can be changed using the <strong> <em>seed()</em> </strong> method. However, it is recommended to use a <strong> <em>random_device</em> </strong> to obtain a seed value for better randomness.</p> <p>The <strong> <em>uniform_int_distribution</em> </strong> class generates random integers with a uniform distribution within a given range. In this code, we have specified the range as <strong> <em>1</em> </strong> to <strong> <em>10</em> </strong> using the constructor.</p> <p>This method provides better randomness and a uniform distribution of generated numbers compared to the <strong> <em>rand()</em> </strong> function. However, it is slower and more complex to implement.</p> <h3>Method 3:</h3> <p> <strong>Using modulo operator with time():</strong> </p> <p>Another method to generate a random number between 1 and 10 is the <strong> <em>modulo operator</em> </strong> with the current time as a seed value. This method is similar to the first method using <strong> <em>rand()</em> </strong> function, but it uses a more random seed value and provides better randomness.</p> <p> <strong>Example:</strong> </p> <p>Let's take an example to generate a random number between 1 and 10 using the modulo operator with <strong> <em>time()</em> </strong> , we can use the following code:</p> <pre> #include #include using namespace std; int main() { srand(time(0)); cout<< 'Random number between 1 and 10 is: ' <<endl; for(int i="0;i<10;i++)" cout << (rand() % 10) + 1<<' '; return 0; } < pre> <p> <strong>Output</strong> </p> <pre> Random number between 1 and 10 is: 6 6 3 6 10 10 1 7 6 4 </pre> <p>In this code, we have used the <strong> <em>time()</em> </strong> function to obtain the current time as a seed value for the <strong> <em>srand()</em> </strong> function. The <strong> <em>srand()</em> </strong> function is used to initialize the random number generator. The <strong> <em>rand()</em> </strong> function generates a random integer between 0 and <strong> <em>RAND_MAX</em> </strong> , which is then limited to a range between 1 and 10 using the <strong> <em>modulo operator</em> </strong> and adding 1 to it.</p> <h2>Conclusion:</h2> <p>In conclusion, there are several methods to generate random numbers between 1 and 10 in C++. The choice of method depends on the requirements of the application, such as <strong> <em>speed, randomness</em> </strong> , and <strong> <em>uniformity</em> </strong> of generated numbers. While the <strong> <em>rand()</em> </strong> function is the simplest and easiest to implement, it may not provide good randomness and uniformity. The <strong> <em></em> </strong> library provides a better way to generate random numbers with a uniform distribution, but it is slower and more complex to implement. The <strong> <em>XORShift</em> </strong> algorithm provides good <strong> <em>randomness</em> </strong> and <strong> <em>uniformity</em> </strong> , but it is more complex to implement and may not be as fast as the <strong> <em>rand()</em> </strong> function.</p> <hr></endl;></pre></random_number<<endl;></pre></endl;> I denne kode har vi inkluderet og header-filer. Det srand() funktionen bruges til at initialisere tilfældig talgeneratoren med den aktuelle tid som frø. Det sikrer, at hver gang programmet køres, genereres en ny sekvens af tilfældige tal.
Det rand() funktion bruges til at generere et tilfældigt heltal mellem 0 og RAND_MAX . For at begrænse intervallet mellem 1 og 10 tager vi resten af dette tal, når det divideres med 10, og lægger 1 til det.
Metode 2:
Brug af C++11 tilfældigt bibliotek
Det C++11 standard introducerede et nyt bibliotek kaldet der giver en bedre måde at generere tilfældige tal på. Dette bibliotek giver flere tilfældige talgenereringsmotorer og distributioner, der kan generere tilfældige tal med en ensartet fordeling.
Eksempel:
Lad os tage et eksempel for at generere et tilfældigt tal mellem 1 og 10 ved hjælp af bibliotek, kan vi bruge følgende kode:
#include #include using namespace std; int main() { random_device rand; mt19937 gen(rand()); uniform_int_distributiondis(1, 10); int random_number = dis(gen); cout<< 'Random number between 1 and 10 is: ' <<random_number<<endl; return 0; } < pre> <p>In this code, we have included the <strong> <em></em> </strong> header file. The <strong> <em>random_device</em> </strong> class is used to obtain a seed value for the random number generator. The <strong> <em>mt19937</em> </strong> class is a random number generation engine that produces random numbers with a uniform distribution. The <strong> <em>uniform_int_distribution</em> </strong> class is used to generate random integers within a given range.</p> <p>By default, the <strong> <em>mt19937</em> </strong> engine uses a seed value of <strong> <em>5489</em> </strong> , which can be changed using the <strong> <em>seed()</em> </strong> method. However, it is recommended to use a <strong> <em>random_device</em> </strong> to obtain a seed value for better randomness.</p> <p>The <strong> <em>uniform_int_distribution</em> </strong> class generates random integers with a uniform distribution within a given range. In this code, we have specified the range as <strong> <em>1</em> </strong> to <strong> <em>10</em> </strong> using the constructor.</p> <p>This method provides better randomness and a uniform distribution of generated numbers compared to the <strong> <em>rand()</em> </strong> function. However, it is slower and more complex to implement.</p> <h3>Method 3:</h3> <p> <strong>Using modulo operator with time():</strong> </p> <p>Another method to generate a random number between 1 and 10 is the <strong> <em>modulo operator</em> </strong> with the current time as a seed value. This method is similar to the first method using <strong> <em>rand()</em> </strong> function, but it uses a more random seed value and provides better randomness.</p> <p> <strong>Example:</strong> </p> <p>Let's take an example to generate a random number between 1 and 10 using the modulo operator with <strong> <em>time()</em> </strong> , we can use the following code:</p> <pre> #include #include using namespace std; int main() { srand(time(0)); cout<< 'Random number between 1 and 10 is: ' <<endl; for(int i="0;i<10;i++)" cout << (rand() % 10) + 1<<\' \'; return 0; } < pre> <p> <strong>Output</strong> </p> <pre> Random number between 1 and 10 is: 6 6 3 6 10 10 1 7 6 4 </pre> <p>In this code, we have used the <strong> <em>time()</em> </strong> function to obtain the current time as a seed value for the <strong> <em>srand()</em> </strong> function. The <strong> <em>srand()</em> </strong> function is used to initialize the random number generator. The <strong> <em>rand()</em> </strong> function generates a random integer between 0 and <strong> <em>RAND_MAX</em> </strong> , which is then limited to a range between 1 and 10 using the <strong> <em>modulo operator</em> </strong> and adding 1 to it.</p> <h2>Conclusion:</h2> <p>In conclusion, there are several methods to generate random numbers between 1 and 10 in C++. The choice of method depends on the requirements of the application, such as <strong> <em>speed, randomness</em> </strong> , and <strong> <em>uniformity</em> </strong> of generated numbers. While the <strong> <em>rand()</em> </strong> function is the simplest and easiest to implement, it may not provide good randomness and uniformity. The <strong> <em></em> </strong> library provides a better way to generate random numbers with a uniform distribution, but it is slower and more complex to implement. The <strong> <em>XORShift</em> </strong> algorithm provides good <strong> <em>randomness</em> </strong> and <strong> <em>uniformity</em> </strong> , but it is more complex to implement and may not be as fast as the <strong> <em>rand()</em> </strong> function.</p> <hr></endl;></pre></random_number<<endl;> I denne kode har vi brugt tid() funktion for at få den aktuelle tid som en startværdi for srand() fungere. Det srand() funktionen bruges til at initialisere tilfældige talgeneratoren. Det rand() funktion genererer et tilfældigt heltal mellem 0 og RAND_MAX , som derefter er begrænset til et område mellem 1 og 10 ved hjælp af operatørmodul og tilføje 1 til det.
Konklusion:
Som konklusion er der flere metoder til at generere tilfældige tal mellem 1 og 10 i C++. Valget af metode afhænger af ansøgningens krav, som f.eks hastighed, tilfældighed , og ensartethed af genererede tal. Mens rand() funktionen er den enkleste og nemmeste at implementere, den giver måske ikke god tilfældighed og ensartethed. Det bibliotek giver en bedre måde at generere tilfældige tal med en ensartet fordeling, men det er langsommere og mere komplekst at implementere. Det XORShift algoritme giver god tilfældighed og ensartethed , men det er mere komplekst at implementere og er måske ikke så hurtigt som rand() fungere.