Šajā tēmā mēs uzzināsim par nejaušības funkciju un to, kā mēs varam ģenerēt nejaušo skaitli C programmēšanas valodā. Kā zināms, izlases funkciju izmanto, lai atrastu nejaušo skaitli starp jebkuriem diviem definētiem skaitļiem. C programmēšanas valodā izlases funkcijai ir divas iebūvētas funkcijas: funkcija rand () un srand (). Sapratīsim šīs funkcijas C valodā.
rand() funkcija
Iekš C programmēšanas valoda , funkcija rand() ir bibliotēkas funkcija, kas ģenerē nejaušo skaitli diapazonā [0, RAND_MAX]. Kad programmā izmantojam funkciju rand(), mums ir jāievieš stdlib.h galvenes fails, jo rand() funkcija ir definēta stdlib galvenes failā. Tas nesatur sēklas numuru. Tāpēc, kad mēs atkal un atkal izpildām vienu un to pašu programmu, tā atgriež tās pašas vērtības.
formāta virkne java
Piezīme. Ja nejaušie skaitļi tiek ģenerēti ar funkciju rand(), neizsaucot funkciju srand(), tā atgriež tās pašas skaitļu virknes katru reizi, kad programma tiek izpildīta.
Sintakse
int rand (void)
Funkcija rand() atgriež nejaušus veselus skaitļus, kuru diapazons ir no 0 līdz RAND_MAX. RAND_MAX ir simboliska konstante, kas noteikta galvenes failā stdlib.h un kuras vērtība ir lielāka, bet mazāka par 32767 atkarībā no C bibliotēkām.
Ģenerējiet nejaušos skaitļus, izmantojot funkciju rand().
Uzrakstīsim programmu nejaušā skaitļa iegūšanai, izmantojot funkciju rand().
vai
#include #include #include void main() { // use rand() function to generate the number printf (' The random number is: %d', rand()); printf ('
The random number is: %d', rand()); printf ('
The random number is: %d', rand()); printf ('
The random number is: %d', rand()); getch(); } Izvade
The random number is: 41 The random number is: 18467 The random number is: 6334 The random number is: 26500
Ģenerējiet 5 nejaušus skaitļus, izmantojot funkciju rand ().
Apskatīsim programmu, kas ģenerē 5 nejaušus skaitļus, izmantojot rand() funkciju C programmēšanas valodā.
nejauši.c
#include #include int main() { int i; /* It returns the same sequence of random number on every execution of the program. */ printf(' Random Numbers are:
'); for (i = 0; i <5; i++) { printf(' %d', rand()); } return 0; < pre> <p> <strong>Output</strong> </p> <pre> Random Numbers are: 41 18467 6334 26500 19169 </pre> <p> <strong>2nd execution of the program:</strong> </p> <pre> Random Numbers are: 41 18467 6334 26500 19169 </pre> <p> <strong>3rd execution of the program</strong> </p> <pre> Random Numbers are: 41 18467 6334 26500 19169 </pre> <p>As we can see in the above output, it returns the same sequence of random numbers on every execution of the programming code.</p> <h3>Generate 10 random numbers from 1 to 100 using rand() function</h3> <p>Let's consider a program to find the random number in C using rand() function.</p> <p> <strong>rand_num.c</strong> </p> <pre> #include #include #include int main() { // declare the local variables int i, num; printf (' Program to get the random number from 1 to 100
'); for (i = 1; i <= 100 10; i++) { num="rand()" % + 1; use rand() function to get the random number printf (' %d ', num); getch(); } < pre> <p> <strong>Output</strong> </p> <pre> Program to get the random number from 1 to 100 42 68 35 1 70 25 79 59 63 65 </pre> <h2>srand() function</h2> <p>The srand() function is a C library function that determines the initial point to generate different series of pseudo-random numbers. A srand() function cannot be used without using a rand() function. The srand() function is required to set the value of the seed only once in a program to generate the different results of random integers before calling the rand() function.</p> <h3>Syntax</h3> <pre> int srand (unsigned int seed) </pre> <p> <strong>seed</strong> : It is an integer value that contains a seed for a new sequence of pseudo-random numbers.</p> <h3>Generate the random numbers using srand() function</h3> <p>Let's write a program to get the random numbers using srand() function in C.</p> <p> <strong>srandNum.c</strong> </p> <pre> #include #include #include // use time.h header file to use time int main() { int num, i; time_t t1; // declare time variable printf(' Enter a number to set the limit for a random number
'); scanf (' %d', &num); /* define the random number generator */ srand ( (unsigned) time (&t1)); // pass the srand() parameter printf('
'); // print the space /* generate random number between 0 to 50 */ for (i = 0; i <num; i++) { printf( '%d
', rand() % 50); } return 0; < pre> <p> <strong>Output</strong> </p> <pre> Enter a number to set the limit for a random number 10 44 32 23 35 6 33 1 4 22 18 </pre> <p> <strong>2nd execution of the program:</strong> </p> <pre> Enter a number to set the limit for a random number 15 13 30 24 27 4 30 28 35 36 13 44 39 21 5 7 </pre> <p>As we can see in the above Output, it returns different sequences of random numbers on every execution of the programming code.</p> <h3>Generate the random numbers using srand() and time() function</h3> <p>Let's write a program to get the random numbers using srand() with time() function.</p> <p> <strong>srand_time.c</strong> </p> <pre> #include #include int main() { int random = rand(); // assign the rand() function to random variable srand( time(0)); printf( ' Seed = %d', time(0)); printf( ' Random number = %d', random); return 0; } </pre> <p> <strong>Output</strong> </p> <pre> Seed = 1619450091 Random number = 41 </pre> <h3>Get a seeding value and print the random numbers using srand() function</h3> <p>Let's write a program to get the seed value and random numbers using srand() function.</p> <p> <strong>srand_time.c</strong> </p> <pre> #include #include int main() { int count; unsigned int seed; // use for randomize number printf(' Enter the Seeding value:
'); scanf(' %u', &seed); srand (seed); // pass parameter // generate random number between 1 to 6 for (count = 1; count <= 1 5="=" 10; ++count) { printf(' %5d', + (rand () % 6)); if (count 0) print the number in next line puts(' '); } return 0; < pre> <p> <strong>Output</strong> </p> <pre> Enter the Seeding value: 10 6 4 3 3 6 3 3 1 3 4 </pre> <p> <strong>2nd execution of the program:</strong> </p> <pre> Enter the Seeding value: 20 2 4 2 4 5 4 3 5 1 4 </pre> <p> <strong>3rd execution of the program:</strong> </p> <pre> Enter the Seeding value: 25 1 6 1 6 4 4 1 4 1 3 </pre> <p>As we can see in the above Output, when we executed the same program again and again with different seeds values, it displays the different sequences of a random number from 1 to 6.</p> <h3>Generate the random number using the random function</h3> <p>Let's create a program to use stadlib header file to get the random number using random function in C.</p> <p> <strong>func.c</strong> </p> <pre> #include #include #include int main() { int i, num, max, temp; printf (' Enter a number to set the limit of random numbers
'); scanf ('%d', num); printf (' Enter the maximum number from you want to get the random number:
'); scanf ('%d', max); printf (' %d random number from 0 to %d number are:
', num, max); randomize(); for (i = 1; i <= num; i++) { temp="random(max)" * use random() function to get the random number printf (' %d ', temp); print } getch(); < pre> <p> <strong>Output</strong> </p> <pre> Enter a number to set the limit of random numbers 17 Enter the maximum number from you want to get the random number: 100 15 random number from 0 to 100 number are: 42 68 35 1 70 25 79 59 63 28 75 89 90 43 7 4 65 </pre> <h2>Program to generate float random numbers</h2> <p>Let's consider a program to print the float random numbers in C.</p> <p> <strong>random1.c</strong> </p> <pre> #include #include #include int main() { srand( (unsigned int) time(NULL)); float f1 = 5.0; int i; printf(?Float random numbers are:
?); for (i = 0; i<10; i++) { printf('%f', ((float) rand() rand_max) * f1); printf('
'); } return 0; < pre> <p> <strong>Output</strong> </p> <pre> Float random numbers are: 1.208075 1.658376 4.645070 2.298807 3.117161 0.961486 4.115573 4.336223 2.894833 2.249825 </pre> <hr></10;></pre></=></pre></=></pre></num;></pre></=></pre></5;> 2. programmas izpilde:
Random Numbers are: 41 18467 6334 26500 19169
3. programmas izpilde
Random Numbers are: 41 18467 6334 26500 19169
Kā redzams iepriekš minētajā izvadē, tas atgriež to pašu nejaušo skaitļu secību katrā programmēšanas koda izpildē.
Izmantojot rand() funkciju, ģenerējiet 10 nejaušus skaitļus no 1 līdz 100
Apskatīsim programmu, lai atrastu nejaušo skaitli C, izmantojot funkciju rand().
rand_num.c
#include #include #include int main() { // declare the local variables int i, num; printf (' Program to get the random number from 1 to 100
'); for (i = 1; i <= 100 10; i++) { num="rand()" % + 1; use rand() function to get the random number printf (\' %d \', num); getch(); } < pre> <p> <strong>Output</strong> </p> <pre> Program to get the random number from 1 to 100 42 68 35 1 70 25 79 59 63 65 </pre> <h2>srand() function</h2> <p>The srand() function is a C library function that determines the initial point to generate different series of pseudo-random numbers. A srand() function cannot be used without using a rand() function. The srand() function is required to set the value of the seed only once in a program to generate the different results of random integers before calling the rand() function.</p> <h3>Syntax</h3> <pre> int srand (unsigned int seed) </pre> <p> <strong>seed</strong> : It is an integer value that contains a seed for a new sequence of pseudo-random numbers.</p> <h3>Generate the random numbers using srand() function</h3> <p>Let's write a program to get the random numbers using srand() function in C.</p> <p> <strong>srandNum.c</strong> </p> <pre> #include #include #include // use time.h header file to use time int main() { int num, i; time_t t1; // declare time variable printf(' Enter a number to set the limit for a random number
'); scanf (' %d', &num); /* define the random number generator */ srand ( (unsigned) time (&t1)); // pass the srand() parameter printf('
'); // print the space /* generate random number between 0 to 50 */ for (i = 0; i <num; i++) { printf( \'%d
\', rand() % 50); } return 0; < pre> <p> <strong>Output</strong> </p> <pre> Enter a number to set the limit for a random number 10 44 32 23 35 6 33 1 4 22 18 </pre> <p> <strong>2nd execution of the program:</strong> </p> <pre> Enter a number to set the limit for a random number 15 13 30 24 27 4 30 28 35 36 13 44 39 21 5 7 </pre> <p>As we can see in the above Output, it returns different sequences of random numbers on every execution of the programming code.</p> <h3>Generate the random numbers using srand() and time() function</h3> <p>Let's write a program to get the random numbers using srand() with time() function.</p> <p> <strong>srand_time.c</strong> </p> <pre> #include #include int main() { int random = rand(); // assign the rand() function to random variable srand( time(0)); printf( ' Seed = %d', time(0)); printf( ' Random number = %d', random); return 0; } </pre> <p> <strong>Output</strong> </p> <pre> Seed = 1619450091 Random number = 41 </pre> <h3>Get a seeding value and print the random numbers using srand() function</h3> <p>Let's write a program to get the seed value and random numbers using srand() function.</p> <p> <strong>srand_time.c</strong> </p> <pre> #include #include int main() { int count; unsigned int seed; // use for randomize number printf(' Enter the Seeding value:
'); scanf(' %u', &seed); srand (seed); // pass parameter // generate random number between 1 to 6 for (count = 1; count <= 1 5="=" 10; ++count) { printf(\' %5d\', + (rand () % 6)); if (count 0) print the number in next line puts(\' \'); } return 0; < pre> <p> <strong>Output</strong> </p> <pre> Enter the Seeding value: 10 6 4 3 3 6 3 3 1 3 4 </pre> <p> <strong>2nd execution of the program:</strong> </p> <pre> Enter the Seeding value: 20 2 4 2 4 5 4 3 5 1 4 </pre> <p> <strong>3rd execution of the program:</strong> </p> <pre> Enter the Seeding value: 25 1 6 1 6 4 4 1 4 1 3 </pre> <p>As we can see in the above Output, when we executed the same program again and again with different seeds values, it displays the different sequences of a random number from 1 to 6.</p> <h3>Generate the random number using the random function</h3> <p>Let's create a program to use stadlib header file to get the random number using random function in C.</p> <p> <strong>func.c</strong> </p> <pre> #include #include #include int main() { int i, num, max, temp; printf (' Enter a number to set the limit of random numbers
'); scanf ('%d', num); printf (' Enter the maximum number from you want to get the random number:
'); scanf ('%d', max); printf (' %d random number from 0 to %d number are:
', num, max); randomize(); for (i = 1; i <= num; i++) { temp="random(max)" * use random() function to get the random number printf (\' %d \', temp); print } getch(); < pre> <p> <strong>Output</strong> </p> <pre> Enter a number to set the limit of random numbers 17 Enter the maximum number from you want to get the random number: 100 15 random number from 0 to 100 number are: 42 68 35 1 70 25 79 59 63 28 75 89 90 43 7 4 65 </pre> <h2>Program to generate float random numbers</h2> <p>Let's consider a program to print the float random numbers in C.</p> <p> <strong>random1.c</strong> </p> <pre> #include #include #include int main() { srand( (unsigned int) time(NULL)); float f1 = 5.0; int i; printf(?Float random numbers are:
?); for (i = 0; i<10; i++) { printf(\'%f\', ((float) rand() rand_max) * f1); printf(\'
\'); } return 0; < pre> <p> <strong>Output</strong> </p> <pre> Float random numbers are: 1.208075 1.658376 4.645070 2.298807 3.117161 0.961486 4.115573 4.336223 2.894833 2.249825 </pre> <hr></10;></pre></=></pre></=></pre></num;></pre></=> srand() funkcija
Funkcija srand () ir C bibliotēkas funkcija, kas nosaka sākuma punktu, lai ģenerētu dažādas pseidogadījuma skaitļu sērijas. Funkciju srand() nevar izmantot, neizmantojot funkciju rand(). Funkcija srand() ir nepieciešama, lai programmā iestatītu sākuma vērtību tikai vienu reizi, lai pirms funkcijas rand() izsaukšanas ģenerētu dažādus nejaušu veselu skaitļu rezultātus.
Sintakse
int srand (unsigned int seed)
sēklas : tā ir vesela skaitļa vērtība, kas satur jaunu pseidogadījuma skaitļu secību.
Ģenerējiet nejaušos skaitļus, izmantojot funkciju srand ().
Uzrakstīsim programmu, lai iegūtu nejaušos skaitļus, izmantojot srand() funkciju C.
raksturs.salīdzināt java
srandNum.c
#include #include #include // use time.h header file to use time int main() { int num, i; time_t t1; // declare time variable printf(' Enter a number to set the limit for a random number
'); scanf (' %d', &num); /* define the random number generator */ srand ( (unsigned) time (&t1)); // pass the srand() parameter printf('
'); // print the space /* generate random number between 0 to 50 */ for (i = 0; i <num; i++) { printf( \'%d
\', rand() % 50); } return 0; < pre> <p> <strong>Output</strong> </p> <pre> Enter a number to set the limit for a random number 10 44 32 23 35 6 33 1 4 22 18 </pre> <p> <strong>2nd execution of the program:</strong> </p> <pre> Enter a number to set the limit for a random number 15 13 30 24 27 4 30 28 35 36 13 44 39 21 5 7 </pre> <p>As we can see in the above Output, it returns different sequences of random numbers on every execution of the programming code.</p> <h3>Generate the random numbers using srand() and time() function</h3> <p>Let's write a program to get the random numbers using srand() with time() function.</p> <p> <strong>srand_time.c</strong> </p> <pre> #include #include int main() { int random = rand(); // assign the rand() function to random variable srand( time(0)); printf( ' Seed = %d', time(0)); printf( ' Random number = %d', random); return 0; } </pre> <p> <strong>Output</strong> </p> <pre> Seed = 1619450091 Random number = 41 </pre> <h3>Get a seeding value and print the random numbers using srand() function</h3> <p>Let's write a program to get the seed value and random numbers using srand() function.</p> <p> <strong>srand_time.c</strong> </p> <pre> #include #include int main() { int count; unsigned int seed; // use for randomize number printf(' Enter the Seeding value:
'); scanf(' %u', &seed); srand (seed); // pass parameter // generate random number between 1 to 6 for (count = 1; count <= 1 5="=" 10; ++count) { printf(\' %5d\', + (rand () % 6)); if (count 0) print the number in next line puts(\' \'); } return 0; < pre> <p> <strong>Output</strong> </p> <pre> Enter the Seeding value: 10 6 4 3 3 6 3 3 1 3 4 </pre> <p> <strong>2nd execution of the program:</strong> </p> <pre> Enter the Seeding value: 20 2 4 2 4 5 4 3 5 1 4 </pre> <p> <strong>3rd execution of the program:</strong> </p> <pre> Enter the Seeding value: 25 1 6 1 6 4 4 1 4 1 3 </pre> <p>As we can see in the above Output, when we executed the same program again and again with different seeds values, it displays the different sequences of a random number from 1 to 6.</p> <h3>Generate the random number using the random function</h3> <p>Let's create a program to use stadlib header file to get the random number using random function in C.</p> <p> <strong>func.c</strong> </p> <pre> #include #include #include int main() { int i, num, max, temp; printf (' Enter a number to set the limit of random numbers
'); scanf ('%d', num); printf (' Enter the maximum number from you want to get the random number:
'); scanf ('%d', max); printf (' %d random number from 0 to %d number are:
', num, max); randomize(); for (i = 1; i <= num; i++) { temp="random(max)" * use random() function to get the random number printf (\' %d \', temp); print } getch(); < pre> <p> <strong>Output</strong> </p> <pre> Enter a number to set the limit of random numbers 17 Enter the maximum number from you want to get the random number: 100 15 random number from 0 to 100 number are: 42 68 35 1 70 25 79 59 63 28 75 89 90 43 7 4 65 </pre> <h2>Program to generate float random numbers</h2> <p>Let's consider a program to print the float random numbers in C.</p> <p> <strong>random1.c</strong> </p> <pre> #include #include #include int main() { srand( (unsigned int) time(NULL)); float f1 = 5.0; int i; printf(?Float random numbers are:
?); for (i = 0; i<10; i++) { printf(\'%f\', ((float) rand() rand_max) * f1); printf(\'
\'); } return 0; < pre> <p> <strong>Output</strong> </p> <pre> Float random numbers are: 1.208075 1.658376 4.645070 2.298807 3.117161 0.961486 4.115573 4.336223 2.894833 2.249825 </pre> <hr></10;></pre></=></pre></=></pre></num;> 2. programmas izpilde:
Enter a number to set the limit for a random number 15 13 30 24 27 4 30 28 35 36 13 44 39 21 5 7
Kā redzams iepriekš minētajā izvadē, tas atgriež dažādas nejaušu skaitļu secības katrā programmēšanas koda izpildē.
Ģenerējiet nejaušos skaitļus, izmantojot funkcijas srand () un time ().
Uzrakstīsim programmu nejaušo skaitļu iegūšanai, izmantojot srand() ar funkciju time().
srand_time.c
#include #include int main() { int random = rand(); // assign the rand() function to random variable srand( time(0)); printf( ' Seed = %d', time(0)); printf( ' Random number = %d', random); return 0; } Izvade
Seed = 1619450091 Random number = 41
Iegūstiet sēšanas vērtību un izdrukājiet nejaušos skaitļus, izmantojot funkciju srand ().
Uzrakstīsim programmu, lai iegūtu sākotnējo vērtību un nejaušos skaitļus, izmantojot funkciju srand().
srand_time.c
#include #include int main() { int count; unsigned int seed; // use for randomize number printf(' Enter the Seeding value:
'); scanf(' %u', &seed); srand (seed); // pass parameter // generate random number between 1 to 6 for (count = 1; count <= 1 5="=" 10; ++count) { printf(\' %5d\', + (rand () % 6)); if (count 0) print the number in next line puts(\' \'); } return 0; < pre> <p> <strong>Output</strong> </p> <pre> Enter the Seeding value: 10 6 4 3 3 6 3 3 1 3 4 </pre> <p> <strong>2nd execution of the program:</strong> </p> <pre> Enter the Seeding value: 20 2 4 2 4 5 4 3 5 1 4 </pre> <p> <strong>3rd execution of the program:</strong> </p> <pre> Enter the Seeding value: 25 1 6 1 6 4 4 1 4 1 3 </pre> <p>As we can see in the above Output, when we executed the same program again and again with different seeds values, it displays the different sequences of a random number from 1 to 6.</p> <h3>Generate the random number using the random function</h3> <p>Let's create a program to use stadlib header file to get the random number using random function in C.</p> <p> <strong>func.c</strong> </p> <pre> #include #include #include int main() { int i, num, max, temp; printf (' Enter a number to set the limit of random numbers
'); scanf ('%d', num); printf (' Enter the maximum number from you want to get the random number:
'); scanf ('%d', max); printf (' %d random number from 0 to %d number are:
', num, max); randomize(); for (i = 1; i <= num; i++) { temp="random(max)" * use random() function to get the random number printf (\' %d \', temp); print } getch(); < pre> <p> <strong>Output</strong> </p> <pre> Enter a number to set the limit of random numbers 17 Enter the maximum number from you want to get the random number: 100 15 random number from 0 to 100 number are: 42 68 35 1 70 25 79 59 63 28 75 89 90 43 7 4 65 </pre> <h2>Program to generate float random numbers</h2> <p>Let's consider a program to print the float random numbers in C.</p> <p> <strong>random1.c</strong> </p> <pre> #include #include #include int main() { srand( (unsigned int) time(NULL)); float f1 = 5.0; int i; printf(?Float random numbers are:
?); for (i = 0; i<10; i++) { printf(\'%f\', ((float) rand() rand_max) * f1); printf(\'
\'); } return 0; < pre> <p> <strong>Output</strong> </p> <pre> Float random numbers are: 1.208075 1.658376 4.645070 2.298807 3.117161 0.961486 4.115573 4.336223 2.894833 2.249825 </pre> <hr></10;></pre></=></pre></=> 2. programmas izpilde:
Enter the Seeding value: 20 2 4 2 4 5 4 3 5 1 4
Programmas 3. izpilde:
Enter the Seeding value: 25 1 6 1 6 4 4 1 4 1 3
Kā redzams iepriekš sniegtajā izvadē, kad mēs atkal un atkal izpildām vienu un to pašu programmu ar dažādām sākuma vērtībām, tā parāda dažādas nejauša skaitļa secības no 1 līdz 6.
Ģenerējiet nejaušo skaitli, izmantojot nejaušības funkciju
Izveidosim programmu, lai izmantotu stadlib galvenes failu, lai iegūtu nejaušo skaitli, izmantojot izlases funkciju C.
func.c
#include #include #include int main() { int i, num, max, temp; printf (' Enter a number to set the limit of random numbers
'); scanf ('%d', num); printf (' Enter the maximum number from you want to get the random number:
'); scanf ('%d', max); printf (' %d random number from 0 to %d number are:
', num, max); randomize(); for (i = 1; i <= num; i++) { temp="random(max)" * use random() function to get the random number printf (\' %d \', temp); print } getch(); < pre> <p> <strong>Output</strong> </p> <pre> Enter a number to set the limit of random numbers 17 Enter the maximum number from you want to get the random number: 100 15 random number from 0 to 100 number are: 42 68 35 1 70 25 79 59 63 28 75 89 90 43 7 4 65 </pre> <h2>Program to generate float random numbers</h2> <p>Let's consider a program to print the float random numbers in C.</p> <p> <strong>random1.c</strong> </p> <pre> #include #include #include int main() { srand( (unsigned int) time(NULL)); float f1 = 5.0; int i; printf(?Float random numbers are:
?); for (i = 0; i<10; i++) { printf(\'%f\', ((float) rand() rand_max) * f1); printf(\'
\'); } return 0; < pre> <p> <strong>Output</strong> </p> <pre> Float random numbers are: 1.208075 1.658376 4.645070 2.298807 3.117161 0.961486 4.115573 4.336223 2.894833 2.249825 </pre> <hr></10;></pre></=> Programma, lai ģenerētu nejaušus skaitļus
Apskatīsim programmu, kas drukātu peldošos nejaušos skaitļus C.
nejaušs1.c
#include #include #include int main() { srand( (unsigned int) time(NULL)); float f1 = 5.0; int i; printf(?Float random numbers are:
?); for (i = 0; i<10; i++) { printf(\\'%f\\', ((float) rand() rand_max) * f1); printf(\\'
\\'); } return 0; < pre> <p> <strong>Output</strong> </p> <pre> Float random numbers are: 1.208075 1.658376 4.645070 2.298807 3.117161 0.961486 4.115573 4.336223 2.894833 2.249825 </pre> <hr></10;>