Given an upper bound in array - elementsGroupItemsCount, for example, which has 101 elements. How would I randomly select a minimum and maximum value from this range 0-100, where the minimum and maximum value are n numbers apart and need to contain n elements.
E.g. if the numbers need to be contain 6 elements, the following would be valid solutions:
I've seen how to generate random numbers in a range, but not sets of random numbers that are interrelated to each other.
As per Bob's comment it looks like you just need to get a random number between 0 and the array length (less the required span) for your lower limit and then add the required span back to it for the upper limit. e.g.
let myArray = [];
for (let i = 0; i<101; i++){
myArray.push({objectID:i})
}
let requiredSpan = 6;
let lowerBand = Math.floor(Math.random()*(myArray.length-requiredSpan));
let upperBand = lowerBand + requiredSpan-1;
console.log(lowerBand, upperBand);
Just to complete the Mark Taylor's Answer here a more reusable way
let myArray = [];
for (let i = 0; i<101; i++){
myArray.push({objectID:i})
}
const randomMaxMin = max => min => Math.floor(Math.random()*(max-min))
const lowerBand = requiredSpan => length => randomMaxMin(length)(requiredSpan);
const upperBand = requiredSpan => lowerBand => requiredSpan + lowerBand-1;
const getLowerAndUpperBand = requiredSpan => length => {
const lower = lowerBand(requiredSpan)(length);
return {
lower: lower,
upper: upperBand(requiredSpan)(lower)
}
}
console.log(getLowerAndUpperBand(6)(myArray.length))
You can even specialize the generic function by choosing the requiredSpan
const getLowerAndUpperBandSix = getLowerAndUpperBand(6)
console.log(getLowerAndUpperBandSix(myArray.length))
getNRandomNumbers = (elementsGroupItems,requiredSpan) => {
var result = []
var startingValue = elementsGroupItems[0]
var endingValue = elementsGroupItems[elementsGroupItems.length -1]
var initialNum = startingValue + Math.floor(Math.random()*(endingValue - requiredSpan))
for(let i=initialNum; i< (initialNum+requiredSpan); i++){
result.push(i)
}
return result
}
console.log(getNRandomNumbers([1,2,3,4],2)) //example
n is not defined and for (int i ...) will throw a syntax error. Please review your code before to share it.
int i -> let i. Because int is unexpected identifier.
[lower, upper], and you wantnnumbers between those 2 bounds? can you please make a more formal example? like a function prototype, a sample input, and the expected output?nto it to generate the second number? You'll just have to make sure that the first generated number is not to close to the end of the list.