标签：hash 循环 size 步骤 int 思路 highlight 队列 title
如果当前字符流没有存在出现一次的字符，返回#字符。
class Solution
{
public:
//Insert one char from stringstream
void Insert(char ch)
{
++cnt[ch-‘\0‘];
if(cnt[ch-‘\0‘]==1)
data.push(ch);
}
//return the first appearence once char in current stringstream
char FirstAppearingOnce()
{
while(!data.empty() && cnt[data.front()] >=2 ) data.pop();
if(data.empty()) return ‘#‘;
return data.front();
}
Solution() {
memset(cnt,0,sizeof(cnt));
}
private:
queue<char> data;
unsigned cnt[128];
};
自己想到了哈希表，却不知道如何具体落实！
class Solution { public: //Insert one char from stringstream string s; char hash[256]={0}; void Insert(char ch) { s+=ch; hash[ch]++; } //return the first appearence once char in current stringstream char FirstAppearingOnce() { int size=s.size(); for(int i=0;i<size;i++) { if(hash[s[i]]==1) return s[i]; } return ‘#‘; } };
标签：hash 循环 size 步骤 int 思路 highlight 队列 title
原文地址：http://www.cnblogs.com/dd2hm/p/7447065.html
