I dette emnet skal vi lære om tilfeldig funksjon og hvordan vi kan generere det tilfeldige tallet i programmeringsspråket C. Som vi vet, brukes tilfeldig funksjon for å finne det tilfeldige tallet mellom to definerte tall. I programmeringsspråket C har tilfeldig funksjon to innebygde funksjoner: rand() og srand() funksjon. La oss forstå disse funksjonene på C-språket.
rand() funksjon
I C programmeringsspråk , er rand()-funksjonen en bibliotekfunksjon som genererer det tilfeldige tallet i området [0, RAND_MAX]. Når vi bruker rand()-funksjonen i et program, må vi implementere stdlib.h header-fil fordi rand()-funksjonen er definert i stdlib-header-filen. Den inneholder ikke noe frønummer. Derfor, når vi kjører det samme programmet igjen og igjen, returnerer det de samme verdiene.
Merk: Hvis de tilfeldige tallene genereres med rand()-funksjonen uten å kalle opp srand()-funksjonen, returnerer den de samme sekvensene med tall hver gang programmet kjøres.
Syntaks
int rand (void)
Rand()-funksjonen returnerer de tilfeldige heltallene med et område fra 0 til RAND_MAX. RAND_MAX er en symbolsk konstant som definerer i stdlib.h header-fil, hvis verdi er større, men mindre enn 32767, avhengig av C-bibliotekene.
få matriselengde i c
Generer de tilfeldige tallene ved å bruke rand()-funksjonen
La oss skrive et program for å få det tilfeldige tallet ved å bruke rand()-funksjonen.
om
#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(); } Produksjon
The random number is: 41 The random number is: 18467 The random number is: 6334 The random number is: 26500
Generer 5 tilfeldige tall ved å bruke rand()-funksjonen
La oss vurdere et program for å generere 5 tilfeldige tall ved å bruke rand()-funksjonen i programmeringsspråket C.
tilfeldig.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. utførelse av programmet:
Random Numbers are: 41 18467 6334 26500 19169
3. utførelse av programmet
innsettingsnøkkel for laptop
Random Numbers are: 41 18467 6334 26500 19169
Som vi kan se i utgangen ovenfor, returnerer den samme sekvens av tilfeldige tall ved hver kjøring av programmeringskoden.
Generer 10 tilfeldige tall fra 1 til 100 ved å bruke rand()-funksjonen
La oss vurdere et program for å finne det tilfeldige tallet i C ved å bruke rand()-funksjonen.
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() funksjon
srand()-funksjonen er en C-biblioteksfunksjon som bestemmer startpunktet for å generere forskjellige serier med pseudo-tilfeldige tall. En srand()-funksjon kan ikke brukes uten å bruke en rand()-funksjon. srand()-funksjonen er nødvendig for å angi verdien av frøet bare én gang i et program for å generere de forskjellige resultatene av tilfeldige heltall før rand()-funksjonen kalles.
Syntaks
int srand (unsigned int seed)
frø : Det er en heltallsverdi som inneholder et frø for en ny sekvens av pseudo-tilfeldige tall.
Generer de tilfeldige tallene ved å bruke srand()-funksjonen
La oss skrive et program for å få de tilfeldige tallene ved å bruke srand()-funksjonen i C.
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. utførelse av programmet:
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
Som vi kan se i utgangen ovenfor, returnerer den forskjellige sekvenser av tilfeldige tall ved hver kjøring av programmeringskoden.
Generer de tilfeldige tallene ved å bruke funksjonen srand() og time().
La oss skrive et program for å få de tilfeldige tallene ved å bruke srand() med time()-funksjonen.
kaste en streng til int java
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; } Produksjon
Seed = 1619450091 Random number = 41
Få en seeding-verdi og skriv ut de tilfeldige tallene ved å bruke srand()-funksjonen
La oss skrive et program for å få seed-verdien og tilfeldige tall ved å bruke srand()-funksjonen.
sammenligne med streng
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. utførelse av programmet:
Enter the Seeding value: 20 2 4 2 4 5 4 3 5 1 4
Tredje utførelse av programmet:
Enter the Seeding value: 25 1 6 1 6 4 4 1 4 1 3
Som vi kan se i utgangen ovenfor, når vi kjørte det samme programmet igjen og igjen med forskjellige frøverdier, viser det de forskjellige sekvensene av et tilfeldig tall fra 1 til 6.
Generer det tilfeldige tallet ved hjelp av tilfeldig funksjon
La oss lage et program for å bruke stadlib header-fil for å få det tilfeldige tallet ved å bruke tilfeldig funksjon i 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></=> Program for å generere flytende tilfeldige tall
La oss vurdere et program for å skrive ut flytende tilfeldige tall i C.
tilfeldig1.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;>