random number generator array
hey i having problems with solving this question:
Write a program that generates an array of 20 random numbers between 1 and 100. Use a loop to
output the numbers on the screen with a field width of 4 characters. Write code that will reverse the
numbers in the array and then output the numbers to the screen with a copy of the same output loop
used with the original numbers.
Please help
What kind of errors are you getting?
array of 20Code:int arr [20] ;
rand () and srand ()20 random numbers
Use a loopCode:int i ; for (i = 0; i < 20; ++i) { ... }
printf () formattingoutput the numbers on the screen with a field width of 4 characters
A swap () functionreverse the numbers
Or copy them backwards into a second array.
Homework helpPlease help
i have filled the array with random numbers and got it to print with a feild width of 4 characters i just dont know figure out how to print the array data in reverse. this is what i have:
Code:int main() { int array[20], i; for(i = 0; i < 20; i++) { array[i] = (rand() % 100)+1; printf("%4d\n", array[i]); } return 0; }
Write a second loop that starts from the last element to print them.
Look up a C++ Reference and learn How To Ask Questions The Smart WayOriginally Posted by Bjarne Stroustrup (2000-10-14)
hey laserlight
so say the first 3 integers in the array are:
45
100
20
how would i switch all numbers in the array to:
54
001
02
(opposite)?
thankyou for your help
It's easy enough to print numbers in reverse.
Just go
But you're not allowed to do this. You have to reverse the array. So you have to step throuhg half of it, swapping very ith element with the N-i-1th element. It's a bit tricky to get all the cases right.Code:for(i=N-1;i>=0;i--) printf("%d\n", array[i]);
To generate random number on 0 to N-1, the cheap and nasty way is rand() % N. This doesn't give a very good distribution, because rand() isn't truly random and the lower bits are less random than the whole.
So the best way to to say
Code:/* random number on 0-1 minus a tiny epsilon */ #define uniform() (rand()/RAND_MAX+1.0)) /* random number on 0-N */ #define rnd(N) (int) (uniform() * (N))
I'm the author of MiniBasic: How to write a script interpreter and Basic Algorithms
Visit my website for lots of associated C programming resources.
https://github.com/MalcolmMcLean
If you need to reverse the order of the digits in a number you could use a combination of modulo (%) and divisior.
Bye, Andreas
