java 代码

class Solution {
    public char firstNotRepeatingChar(String s) {
        int len = s.length();
        if(len == 0) return '#';
        int[] array = new int[126 - 32];//采用数组来存放位置。如果已存放，则职位-1
        for(int i=0;i<array.length;i++)
            array[i] = -1;
        for (int i = 0; i < len; i++) {
            int index = s.charAt(i) - 32;
            if (array[index] == -1) {
                array[index] = i;
            }else{
                array[index] = -1;
            }
        }
        int min = array.length;
        for (int i = 0; i < array.length; i++) {
            if(array[i] !=-1) {
                if(array[i] < min) min = array[i];
            }
        }
        ;
        return min==array.length?'#':s.charAt(min);
    }
}