Random numbers between -1000 and 1000
For part of a programming that I'm writing, I want to generate random numbers between the range of -1000 and 1000. My teacher never spent much time on the rand function, and I'm not quite sure how to specify a range like that. Any help would be greatly appreciated. Thanks!
rfrapp
Junior Poster in Training
57 posts since Dec 2011
Reputation Points: 27
Solved Threads: 0
randNum = (rand() % range) + firstNum;
range is the total number you want to generate
firstnum is the beginning number of that range
WaltP
Posting Sage w/ dash of thyme
10,506 posts since May 2006
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Sometimes it helps to see concrete examples:
int r1 = rand() ; //random number from [0 , RAND_MAX]
int r2 = rand() % 100; // random number from [0,100); Note doesn't include 100
int r3 = rand() % 100 + 1; //random number from [1,100]; Note includes 100
const int max = 100;
const int min = -100;
int r4 = rand() % (max - min) + min; // random number between [min,max)
When you want to look up a function, you can see examples here . Bookmark it if you need to. Its a good reference
firstPerson
Senior Poster
3,923 posts since Dec 2008
Reputation Points: 841
Solved Threads: 608
Sometimes it helps to see concrete examples:
int r1 = rand() ; //random number from [0 , RAND_MAX]
int r2 = rand() % 100; // random number from [0,100); Note doesn't include 100
int r3 = rand() % 100 + 1; //random number from [1,100]; Note includes 100
const int max = 100;
const int min = -100;
int r4 = rand() % (max - min) + min; // random number between [min,max)
When you want to look up a function, you can see examples here . Bookmark it if you need to. Its a good reference
Thanks! The example worked well! I figured it out now.
rfrapp
Junior Poster in Training
57 posts since Dec 2011
Reputation Points: 27
Solved Threads: 0
Sometimes it helps to see concrete examples:
int r1 = rand() ; //random number from [0 , RAND_MAX]
int r2 = rand() % 100; // random number from [0,100); Note doesn't include 100
int r3 = rand() % 100 + 1; //random number from [1,100]; Note includes 100
const int max = 100;
const int min = -100;
int r4 = rand() % (max - min) + min; // random number between [min,max)
When you want to look up a function, you can see examples here . Bookmark it if you need to. Its a good reference
How do i mark a thread solved? I'm relatively new here :p
rfrapp
Junior Poster in Training
57 posts since Dec 2011
Reputation Points: 27
Solved Threads: 0