class Solution {
    public int[] twoSum(int[] nums, int target) {
        for(int i = 0;i < nums.length;i++){
            for(int j = i + 1;j < nums.length;j++){
                if(nums[i]+nums[j] == target){
                    return new int[]{i,j};
                }
            }
        }
        return new int[]{};
    }
}

class Solution {
    public int lengthOfLongestSubstring(String s) {
        int len = s.length();
        int [] a = new int[len];
        for(int i = len;i > 0;i--){
            for(int j = 1;j <= len+1-i;j++){
                String str = s.substring(j-1,j-1+i); // 获取截取字符串
                HashSet set = new HashSet();
                for(int k = 0;k < i;k++){
                    set.add(str.charAt(k)); // 遍历存入set中
                    if(set.size() != k+1){
                        break;
                    }else if(set.size() == i){
                        return i;
                    }
                }
            }
        }
        return 0;
    }
}