Šioje temoje sužinosime apie atsitiktinę funkciją ir kaip galime sugeneruoti atsitiktinį skaičių C programavimo kalba. Kaip žinome, atsitiktinė funkcija naudojama atsitiktiniam skaičiui tarp bet kurių dviejų apibrėžtų skaičių rasti. C programavimo kalboje atsitiktinė funkcija turi dvi integruotas funkcijas: funkciją rand () ir srand (). Supraskime šias funkcijas C kalba.
rand() funkcija
Viduje C programavimo kalba , funkcija rand() yra bibliotekos funkcija, kuri generuoja atsitiktinį skaičių diapazone [0, RAND_MAX]. Kai programoje naudojame funkciją rand(), turime įdiegti stdlib.h antraštės failą, nes rand() funkcija yra apibrėžta stdlib antraštės faile. Jame nėra sėklos numerio. Todėl, kai vėl ir vėl vykdome tą pačią programą, ji grąžina tas pačias reikšmes.
Pastaba: jei atsitiktiniai skaičiai generuojami naudojant funkciją rand() neiškviečiant funkcijos srand(), ji grąžina tas pačias skaičių sekas kiekvieną kartą, kai programa vykdoma.
Sintaksė
int rand (void)
Funkcija rand() grąžina atsitiktinius sveikuosius skaičius, kurių diapazonas yra nuo 0 iki RAND_MAX. RAND_MAX yra simbolinė konstanta, kuri apibrėžiama stdlib.h antraštės faile, kurios reikšmė yra didesnė, bet mažesnė nei 32767, priklausomai nuo C bibliotekų.
Sugeneruokite atsitiktinius skaičius naudodami rand() funkciją
Parašykime programą atsitiktiniam skaičiui gauti naudodami funkciją rand().
ar
#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(); }
Išvestis
The random number is: 41 The random number is: 18467 The random number is: 6334 The random number is: 26500
Sugeneruokite 5 atsitiktinius skaičius naudodami rand() funkciją
Panagrinėkime programą, kuri generuoja 5 atsitiktinius skaičius naudojant rand() funkciją C programavimo kalba.
atsitiktinis.c
10 procentų iš 60
#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-as programos vykdymas:
Random Numbers are: 41 18467 6334 26500 19169
3 programos vykdymas
Random Numbers are: 41 18467 6334 26500 19169
Kaip matome aukščiau pateiktame išvestyje, jis grąžina tą pačią atsitiktinių skaičių seką kiekvieną kartą vykdant programavimo kodą.
Sugeneruokite 10 atsitiktinių skaičių nuo 1 iki 100 naudodami rand() funkciją
Panagrinėkime programą, skirtą atsitiktiniam skaičiui rasti C naudojant rand() funkciją.
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 () yra C bibliotekos funkcija, kuri nustato pradinį tašką, kad būtų generuojamos skirtingos pseudoatsitiktinių skaičių serijos. Funkcijos srand() negalima naudoti nenaudojant funkcijos rand(). Funkcija srand () reikalinga norint nustatyti pradinės reikšmės reikšmę tik vieną kartą programoje, kad būtų sugeneruoti skirtingi atsitiktinių sveikųjų skaičių rezultatai prieš iškviečiant funkciją rand ().
Sintaksė
int srand (unsigned int seed)
sėkla : tai sveikasis skaičius, kuriame yra naujos pseudoatsitiktinių skaičių sekos pradžia.
Sugeneruokite atsitiktinius skaičius naudodami funkciją srand().
Parašykime programą atsitiktiniams skaičiams gauti naudojant srand() funkciją 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-as programos vykdymas:
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
Kaip matome aukščiau pateiktame išvestyje, jis grąžina skirtingas atsitiktinių skaičių sekas kiekvieną kartą vykdant programavimo kodą.
Sugeneruokite atsitiktinius skaičius naudodami srand() ir time() funkcijas
Parašykime programą atsitiktiniams skaičiams gauti naudojant srand() su time() funkcija.
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; }
Išvestis
Seed = 1619450091 Random number = 41
Gaukite sėjimo vertę ir atspausdinkite atsitiktinius skaičius naudodami funkciją srand ().
Parašykime programą, kuri gautų pradinę vertę ir atsitiktinius skaičius naudodami funkciją 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-as programos vykdymas:
Enter the Seeding value: 20 2 4 2 4 5 4 3 5 1 4
3 programos vykdymas:
Enter the Seeding value: 25 1 6 1 6 4 4 1 4 1 3
Kaip matome aukščiau pateiktame išvestyje, kai vėl ir vėl vykdėme tą pačią programą su skirtingomis sėklų reikšmėmis, ji rodo skirtingas atsitiktinių skaičių nuo 1 iki 6 sekas.
Sugeneruokite atsitiktinį skaičių naudodami atsitiktinės funkcijos funkciją
Sukurkime programą, kuri naudotų stadlib antraštės failą, kad gautume atsitiktinį skaičių naudodami atsitiktinę funkciją 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></=>
Programa generuoti plūduriuojančius atsitiktinius skaičius
Panagrinėkime programą, kuri spausdintų plūduriuojančius atsitiktinius skaičius C.
atsitiktinis1.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;>
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