题目：在一个字符串中找到第一个只出现一次的字符。如输入abaccdeff，则输出b.
核心代码:
<pre><code>`
func findFirstStr(string:String) -> String {
var str:String = string
var dict:[String:Int] = [:]
for i in 0..<str.characters.count {
let char:String = str[i]
if dict.keys.contains(char) {
let count:Int = dict[char]!
dict[char] = count + 1
} else {
dict[char] = 1
}
}
var result:String = ""
for i in 0..<str.characters.count {
let char:String = str[i]
if dict[char]! == 1 {
result = char
break
}
}
return result
}`</code></pre>
测试代码:
<pre><code>var hashSearch:HashSearch = HashSearch() var firstChar:String = hashSearch.findFirstStr(string: "简简单单的FlyElephant") print("第一次只出现一次的字符---\(firstChar)")</code></pre>
