Word ladder: Difference between revisions
Added Swift solution
m (C++ bug fix) |
(Added Swift solution) |
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(john cohn conn cone cane jane)
child into adult cannot be done</pre>
=={{header|Swift}}==
{{trans|Wren}}
<lang swift>import Foundation
func oneAway(string1: String, string2: String) -> Bool {
if string1.count != string2.count {
return false
}
var sum = 0
for (c1, c2) in zip(string1, string2) {
if c1 != c2 {
sum += 1
if sum > 1 {
return false
}
}
}
return sum == 1
}
func wordLadder(words: [String], from: String, to: String) {
var poss = words.filter{$0.count == from.count}
var queue: [[String]] = [[from]]
while !queue.isEmpty {
var curr = queue[0]
let last = curr[curr.count - 1]
queue.removeFirst()
let next = poss.filter{oneAway(string1: $0, string2: last)}
if next.contains(to) {
curr.append(to)
print(curr.joined(separator: " -> "))
return
}
poss.removeAll(where: {next.contains($0)})
for str in next {
var temp = curr
temp.append(str)
queue.append(temp)
}
}
print("\(from) into \(to) cannot be done.")
}
do {
let words = try String(contentsOfFile: "unixdict.txt", encoding: String.Encoding.ascii)
.components(separatedBy: "\n")
.filter{!$0.isEmpty}
wordLadder(words: words, from: "man", to: "boy")
wordLadder(words: words, from: "girl", to: "lady")
wordLadder(words: words, from: "john", to: "jane")
wordLadder(words: words, from: "child", to: "adult")
} catch {
print(error.localizedDescription)
}</lang>
{{out}}
<pre>
man -> ban -> bay -> boy
girl -> gill -> gall -> gale -> gaze -> laze -> lazy -> lady
john -> cohn -> conn -> cone -> cane -> jane
child into adult cannot be done.
</pre>
=={{header|Wren}}==
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