This question already has an answer here:
srand function is returning same values
(1 answer)
Closed 7 years ago.
So I'm generating some random numbers. I'm using
srand(time(NULL));
to generate random numbers. However I have this within a for loop. Im generating 10 'sets' of random numbers, but they are all the same. I was wondering how I could change this line of code to ensure the random numbers each time the program goes round the loop.
Already answerd : What you'll want to do is call srand() once, when the program starts (at the start of your main() function)
Then call rand() every time you want a random number
srand function is returning same values
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This question already has answers here:
fgets doesn't work after scanf [duplicate]
(7 answers)
Closed 2 years ago.
discrepency
Hi everyone,
Currently working on some Harvard's CS50 problems, I've noticed that substituting get_int by scanf makes my program behave erratically.
The problem at hand here consists in creating a plurality election mockup. And the simple fact that I replace get_int by scanf in order to register the number of votes during the election ends up signalling the first vote as 'invalid' (a function later in the code is charged of checking vote validity).
I've checked multiple times, used the debugger, but to no avail.
Any hints as to why that happens would be deeply appreciated.
scanf("%i", &vote_count) does not consume anything after the number. What comes after the number is most likely a newline character, which is what will be seen by get_string. That probably causes the first name to be an empty string.
You should see all that if you use a debugger.
This question already has answers here:
Recursion or iteration?
(14 answers)
Closed 2 years ago.
What is the difference between loops and recursion and which one is more preferred for solving a problem?
Loop is repeated execution of a block of code until the given condition is false.Loop has a linear flow from initial condition to terminating condition.
On the other hand recursion is a method/function being called by itself. Recursion takes place creating stack of task ie, each calling function returns to its caller function after execution.
Loop and recursion aren't exactly alternatives to have preferences, they are used for different type of tasks.
This question already has answers here:
Non blocking getch()
(2 answers)
Closed 3 years ago.
I am making a typing game in C Language in this game letters come from the top of the window and user has to type that letter to delete it and to stop it from touching the specific boundary line if it touches the boundary line user lose points and ultimately lose the game. Now I am having trouble to print the list of the characters and take input at the same time. If I tried to use the scanf() or getch() function they both stop the printing process is there any way that I could get input from a user without stopping the printing process.
Kbhit Function really Works for that problem.
This question already has answers here:
C code won't finish running
(4 answers)
Closed 9 years ago.
The purpose of this code is to construct a char Hadamard matrix of the size of my choosing.
This question is related to a previous question I asked. The answer given there was an integer not char matrix, but the code here is pretty much the same format.
The code compiles but when executed it doesn't finish and I don't know why. When executed infinite 2's are printed.
I get the same result when swap the dynamic Hadamard matrix section for one of a fixed size.
Note: I've no idea what your program does, but obviously this is wrong. You failed to actually change the control variable in your for-loop (which can be done in the final expression or the loop body itself).
Change this:
for (ind=1;ind<=sizeH;ind*2)
to this:
for (ind=1;ind<=sizeH;ind*=2) // << note *=
This question already has answers here:
Closed 12 years ago.
Possible Duplicate:
How to generate a random number from within a range - C
I'm looking for something I can use in C that will give me a random number between a and b. So something like rand(50) would give me a number between 1 and 50.
From the comp.lang.c FAQ: How can I get random integers in a certain range?
You can use either rand or random to get an arbitrary random value, then you can take the result of that and mod it by the size of the range and then add the start offset to put it within the desired range. Ex:
(rand()%(b-a))+a
You need to use rand() and srand().
http://linux.die.net/man/3/rand