Given a string, find the first non-repeating character in it and return it's index. If it doesn't exist, return -1.
肯定是要遍历才能知道出现的次数的。
class Solution {
public int firstUniqChar(String s) {
int[] count = new int [26];
int pos =0;
for(int i = 0 ;i<s.length();i++)
{
count[(int)(s.charAt(i)-'a')]++;
}
for(int i = 0 ;i<s.length();i++)
{
if(count[(int)(s.charAt(i)-'a')]==1)
{
return i;//find
}
}
return -1 ;//miss
}
}
