binary search swift
func binarySearch(in numbers: [Int], for value: Int) -> Int?
{
var left = 0
var right = numbers.count - 1
while left <= right {
let middle = Int(floor(Double(left + right) / 2.0))
if numbers[middle] < value {
left = middle + 1
} else if numbers[middle] > value {
right = middle - 1
} else {
return middle
}
}
return nil
}
// useage
let numbers = [2, 3, 5, 7, 11, 13, 17, 19, 23, 29]
let value = 13
if let index = binarySearch(in: numbers, for: value) {
print("Found \(value) at index \(index)")
} else {
print("Did not find \(value)")
}
// Output: Found 13 at index 5