27 lines
546 B
Swift
27 lines
546 B
Swift
if let input = readLine(), let nums = input.split(separator: " ").compactMap({Int($0)}) as? [Int], nums.count == 2 {
|
|
let A: Int = nums[0]
|
|
var B: Int = nums[1]
|
|
|
|
var count: Int = 1
|
|
var flag: Bool = false
|
|
while B >= A {
|
|
if A == B {
|
|
flag = true
|
|
break
|
|
}
|
|
|
|
if B%2 == 0 {
|
|
B /= 2
|
|
count+=1
|
|
}
|
|
else if B%10 == 1 {
|
|
B = (B-1)/10
|
|
count+=1
|
|
}
|
|
else {
|
|
break
|
|
}
|
|
}
|
|
|
|
print(flag ? count : -1)
|
|
} |