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I want to generate random numbers from -n to n excluding 0. Can someone provide me the code in C? How to exclude 0?
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I know this question has been asked time and again. I need random numbers between 0-9. I am using the following code:
srand(time());
int r;
for (;;)
{
while(condition)
...
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For a simple simulation in C, I need to generate exponential random variables. I remember reading somewhere (but I can't find it now, and I don't remember why) that using the ... |
Recently i have begun development of a simple game. It is improved version of an earlier version that i had developed. Large part of the game's success depends on Random number ... |
I know that there are other questions similar to this one, however the following question pertains to arbitrary-precision random number generation in C for use in Monte Carlo simulation.
How can we ... |
While searching for Tutorials on generating random numbers in C I found this topic
When I try to use the rand() function with parameters, I always get 0. When I ... |
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i can generate random number between two numbers in c using this..
arc4random()%(high-low+1)+low;
then now my requirement is...i want to make a number rare....thats mean if
high=5,
low=1,
and rare=3,
than 3 will be ... |
I have looked at how to generate two random ints with rand()%n (where n is the total number of samples) but they seem to usually have a bias.
Is there a better ... |
I would like to generate weighted random numbers in an exact manner. I can explain exact with an example: My input array is [1, 2, 3] and their weights are again ... |
I want to generate pseudorandom numbers in parallel using openMP, something like this:
int i;
#pragma omp parallel for
for (i=0;i<100;i++)
{
printf("%d %d %d\n",i,omp_get_thread_num(),rand());
}
return 0;
I've tested it on windows ... |
I want to generate 2 random numbers between 0 and 20
int one = rand() % 20;
it gives me 1 steady value i.e 1...
Am I missing something?
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I need to generate a random number, now this number needs to be somewhere between 10 and 120 seconds.
Now, in C I could use Random to acomplish this, however I do ... |
I am using rand() function in C. To limit the range I do rand() % 1e6, so that numbers are between 0 and 1e6. A sample set of numbers generated is ... |
I want to generate random numbers between (0,1). I am trying the following:
double r2()
{
return((rand() % 10000) / 10000.0);
}
int SA()
{
double u;
...
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I am writing a program which have to generate N random not repeating numbers
the prototype should be voidrandom_int(int array[], int N);
it is not having any errors but it is not ... |
i need a library with functions for generating random number, given average, standard deviation and using one of three distribution - exponential, normal or unified.
even one of the three would ... |
I need fast way to generate ip numbers that are valid (reserved ips are valid too).
For now i am using this:
unsigned char *p_ip;
unsigned long ul_dst;
p_ip = (unsigned char*) &ul_dst;
for(int i=0;i<sizeof(unsigned long);i++)
...
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I'm trying to run several instances of a piece of code (2000 instances or so) concurrently in a computing cluster. The way it works is that I submit the jobs ... |
I'm looking for a way to generate large random numbers on the order of 2^64 in C... (100000000 - 999999999), to use in a public key encryption algorithm (as p and ... |
I am trying to generate a random number, but it should not be a particular number. So i am passing the number which should not be the random number and the ... |
Im trying to make a program that calculates out a math equation, Im getting stuck on how i generate a random number from 0.00 to 1.00 and store it in a ... |
yes, yes, yes, and thank you so much Rabbit. I was actually thinking on using the operator "+=" on this problem, but I was having doubts. I dug up some info about the running sum that you recommended and it used the operator "+=", so that pretty much solved my problem there. I'll post the complete working code, for future references ... |
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So you want a number X such that 0 <= X <= 1024 and X is even. First question then is how many values are actually in that range? The answer 1024/2 + 1 = 513. So you need to generate 513 unique numbers or a number Y such that 0 <= Y < 513 or a number in the range ... |
srand() does NOT use time to generate random numbers. The argument to srand() is an unsigned int. You can think of this argument as selecting a sequence of random numbers for successive calls to rand() -- a unique sequence for each value of the argument. Sometimes you want to have the same sequence of random numbers each time your program runs. ... |
Sanchit wrote: I want to generate a randowm number between two numbers x and y i.e > int randomNoBetween(int x, int y); The (I guess) simplest way to get a random number in the interval [0, n) (that is, 0 inclusive, n exclusive) is (if n is small enough) probably (rand() % n), which will however slightly favor smaller numbers. I ... |
>I need to generate two uniform random numbers between 0 and 1 in C ? Computers do not generate truly random numbers without hardware support. Some techniques include the detection of radioactive decay and thermal noise from a reverse-biased diode. There is some belief that there is randomness in the timing (say, down to picoseconds) of keystrokes, although I don't think ... |
In my prev. posting I forgot to mention that the random numbers shall be in the range 0 to 99. So here my updated question: What is the correct method for generating 2 independent random numbers in the range 0 to 99 ? They will immediately be compared for equality. What about this method: srand(time(0)); int r1 = rand() % 100; ... |
The best way to deal with a program like this is one issue at a time. As for your do-while loop, its all messed up. My suggestion is ignore the "do" part and replace it with a single while loop. It will look something like while( xxx) { ... }, where xxx is the conditional (you got that right) and ... ... |
I'm writing in C. I am trying to get a simple way to generate a random number between 0 and 1. I'm not sure of two things - how to limit a random number to 0 or 1 and how to reset it every time I hit the "Enter" key. I want to try to do something simple like a coin ... |
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Yeah, you're not actually generating a "random number" per se, but more a pseudo-random number. There are algorithms for getting a very dispersed range, some positive, some negative, etc.... One cool thing is that if you set the seed with the same number, you can come up with the same 'random numbers' each time to duplicate experiments. You probably are getting ... |
I'm new so i apologize if this is in the wrong spot. I'm also new to programming in C and i've been searching for quite a while on how to create a program using C that will generate two random numbers, multiply them, and ask you for the result. It also needs to have four responses for both right and wrong ... |
Yes, it is C#. It does not like my nest while loops. It thinks it is a statement and expects me to put a semicolon at the end of the while statement. Sorry about the code not being in the code brackets. Didn't know I had to do that. This looks like C# code, am I correct? What doesn't work about ... |
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I'm not entirely sure what you're asking for. Do you want a list of random numbers, but each successive number should be smaller? e.g., 1239.295 99.482 83.218 47.671 14.23148 12.184 11.19847 8.193 8.0582 6.2 etc.? Well, here's the simplest way I can think of to do that: float largest_number = 10000; float scale = largest_number; for( int i=0; i < total_count ... |
muttaa said: [color=blue] > Hi everybody, > > May i know how to write a code that generates random numbers as many > times as one would want ? i.e. like the standard function 'rand()' or > may i get the basic logic behind it ?[/color] One common technique is the Linear Congruential PseudoRandom Number Generator. This works on the principle ... |
In article , Mark Healey wrote:[color=blue] >Here's the code:[/color] [color=blue] >signed char xMove, yMove, subx, suby;[/color] [color=blue] >[a bunch of stuff snipped][/color] [color=blue] >xMove=(3*((float)rand()/(float)RAND_MAX))-1; >yMove=(3*((float)rand()/(float)RAND_MAX))-1;[/color] [color=blue] >I run srand() in main. When I run it without the -1 I get 0-2 as expected >but when I run it with them I get 0 and 1.[/color] [color=blue] >Why?[/color] rand() will rarely ... |
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Hey everyone, Having some problems with generating a random number w. I'm using an algorithm to create w by generating two numbers between -1 and 1 and then squaring them and then summing then and then using user in putted means and standard deviations to generate tailor made distributions of random numbers. Here it is: NO code please just advice on ... |
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float r; r = ((float) rand() / RAND_MAX); // generate a random value between 0 and 1 r *= 33.3; // scale this up to the range you want r += 20.2; // slide the range up to the starting value you want r = 20.2 + 33.3 * ((float) rand() / RAND_MAX); // same thing, in one line |
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#include #include #include int main() { srand(time(NULL)); int i, temp, swap_pos, array[52]; for(i=0; i<52; i++)array[i] = i; //Init //Shuffle for(i=51; i>1; i--) { swap_pos = rand() % i; //Pick random location to swap with temp = array[swap_pos]; //Swap elements array[swap_pos] = array[i]; array[i] = temp; } for(i=0; i<52; i++) printf("%02d\n", array[i]); return 0; } |
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Yes, srand() will be set to a number corresponding to current time, and since that is in seconds, it's won't change more than once a second. However, if you want a SEQUENCE of numbers that vary a fair bit, then srand() will set the STARTING POINT, further calls to rand() will be picking different numbers [make a loop that produces 10 ... |
Code: #include #include #include #define RANGE 50 #define BALLS 6 int main() { int numbers[RANGE]; int c, ball; puts("L O T T O P I C K E R\n"); srandom((unsigned)time(NULL)); /* initialize array */ for(c = 0; c < RANGE; c++) numbers[c]=0; printf("Press Enter to pick numbers: "); getchar(); /* draw numbers */ puts("Here they come: "); for(c ... |
Hello friends, Need help in generating random numbers from an array without repeats.Once a number is generated, the number has to be deleted from the array so that only the remaining numbers can be generated from the array the next time we call that function.And it should go on until all the numbers from the array are deleted. The code i ... |
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Hi - I'm not sure if this is "specific to C," but I just had a question for all the C/C++ programmers out there. Currently, in my programs, I generate random numbers using srand() and rand() per usual. However, I am wondering about how good of a random number generator rand() really is. I am beginning to program scientific simulations (thin ... |
Thanks master5001 but I tried your idea and get the same repeated streams of integers with each iteration of the while loop (NB that with each run of the progam and therefore a new seed I get a different but nevertheless repeated series of non-random numbers). Is there a way to seed each independent time I need a number or if ... |
I read the article to much time ago - so I do not remember the reason that Prelude was giving. But If we look at srand - it takes unsigned long So when time() returns 8 bytes value - you will take only half of it... And this half could stay the same for very long time... |
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laser light Code: You should seed the random number generator only once If i am not wrong the reason for manual seeding if i may call is to choose 'numbers of random sequence' i.e. a different starting value in a sequence will lead to different set of numbers of the same sequence {a(n)}.So using 'time' which is constantly variable, i intended ... |
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Hi All, I need your help with Random Number Generating...How can I generate Numbers with a specific length ? I mean...It should ask me: What is the length of the Random Numbers You Want To Generate ?...If I tell 5 for example, then It should generate all Numbers with length 5 digts... Also...May I know the difference between: rand , random ... |
here is the code again: float generare(void) { int r; float U; randomize(); r=random(100); U=r/99; return U; So, randomize initialize the random generator. Then, r gets an integer number between 0 and 99. But i need a random number between 0 and 1 so, i make U=r/99, U is float as the result. Now, if i erase the U=r/99 line, things ... |
Hi, I have made a program that generates random numbers. It takes arguments from the command line like this: Usage: argv[0] [-n | -c [val]] [min-max] [num] Default behaviour is to print [num] random numbers, ranging from [min] to [max], with a newline after each number. The option "-n" will cause no newlines to be printed between each value, OR, "-c ... |
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Greetings, I have been working on ways to create massive amounts of random numbers from 0 to 7. I have been going nuts with rand(). I want to create a program that will print out sets of 8 random numbers (from 0 - 7) until I tell it to stop. Like well over a billion times. I have studied rand() and ... |
__________________ Right 98% of the time, and don't care about the other 3%. It has been said that the great scientific disciplines are examples of giants standing on the shoulders of other giants. It has also been said that the software industry is an example of midgets standing on the toes of other midgets. (Alan Cooper) |
#include main(){ int i; float seed; float rand(float); printf("\nEnter an odd 6 digit number not ending in 5: "); scanf("%f", &seed); for(i = 0; i < 10; i++){ seed = rand(seed); printf("\n%14.6f", seed); } } float rand(float x){ int i; i = 997.0 * x / 1.e6; x = 997.0 * x - i * 1.e6; return x; } |
Since you have only to pick 3, a brute force approach would probably be adequate: Code: num1=rand()%8+1; do { num2=rand()%8+1; } while( num2 == num1 ) ; do { num3=rand()%8+1; } while( num3 == num1 || num3 != num2 ) ; Not pretty, or generally applicable, but possibly good enough in this case. A more general approach might use a container ... |
Hi, I'm trying to do a little something here and I was hoping someone might be able to point me in the right direction. I need to generate a random, 256 bit aes key then use it to encrypt a message 128 bits long. The random generator needs to be my own work so I'm looking for maybe a tutorial or ... |
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Don't really know anything about that distribution but one way to do it might be to figure out the probability of a certain number in the range. To give a simple example, if i'm trying to create a random group of numbers 1-5, such that the probability of the numbers are as such: 1: .1 2: .2 3: .4 4: .2 ... |
u shd call srand only once in the whole execution (as u are giving a constant seed). ..may be u can hv it as the first stmt in main. Otherwise everytime u call the function fire, srand is called again and it will generate the same number (as the seed is same == 100). |
hello, i am stuck once again and need help understanding the linear congruential method of pseudo random number generation. This is what i do know X(n+1) = (aX(n) + c) mod m, n >= 0, and X(0) = s without specifying the values of the equation i will explain my dilema. first of all it says x(0) =s but n is ... |
To my knowledge, neither the C or C++ lib contains a built-in good random number generator. google for 'pseudo random number generator' and you should find tons of examples. It is also very important what you are using the numbers for. If you are doing encryption, you MUST use a crypto secure number generator or you will be introducing bias that ... |
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i want to generate non repeated random numbers from 0 to 156. here is the code for the purpose. but when i try to generate the random numbers more then 1 time by using a for loop, the same pattern on numbers repeats. how to solve this problem ? #include "sys/types.h" #include "stdio.h" #include "time.h" #define MAX 2000 #define N 156 ... |
#include #include #include int main(void) { int i,j,k,l; //loop initilizers int count; //to check for repetition int num; int grid[3][3] = {}; srand(time(NULL)); num = 1 + rand()%9; //generating the array & checking for repetition for(i=1;i=3;i++) { for(j=1;j=3;j++) { for(k=1;k=3;k++) //checking the row for repetition { if(grid[k][j]=num) count++; } for(l=1;l=3;l++) //checking the column for repetition { if(grid[i][l]=num) count++; ... |
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Hey The title is a bit confusing so Ill explain. I have a function that returns random values from 0-4 for the computer (which has numberofplayers). Lets say number of players is 2. One is me and the other is the PC. I (myself thru a scanf and I being player 1) set my value for 2. How can I create ... |
#include #include #define RANGE 100 // for values from 0-99 int main() { int myNum; char s[10]; srand(time()); // "seeds" the generator while(1) // infinite loop (use CTRL-C to break) { // reasonably random number between 0 and RANGE-1 myNum = (int)((double)rand()/(((double)RAND_MAX + 1.0)/ (double)RANGE)); printf("my random number is %02d", myNum); gets(s); // just wait for } // ... |
/* * random_ascii.c */ #include #include #include char *randy( char *ascii, int len ) { char *ptr = ascii; int i; for( i = 0; i < len; i++ ) { *( ptr + i ) = rand() % 94 + 33; } *( ptr + i ) = '\0'; return ptr; } int main( void ) { ... |
#include #include #include using namespace std; int main() { int not1= 0; double sum = 0; while (!not1) { for (int i = 0; i < 12; i ++) { sum = sum + (1/ (((rand()%1214) + 1)); } if ((sum <=1) && (sum > .75)) not1 = 1; } } |
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Hi guys, I'm new in programming and I just started to learn C language. I got this assignment question that requires me to use random number generation. I know how to create a simple random number generation using seed. But this question is giving me a headache. Please spare me some advice. Write a C program to perform the following task: ... |