每日三题-无重复字符的最长子串、最长连续序列、找到字符串中所有字母异位词

class Solution {
    public int lengthOfLongestSubstring(String s) {
        int len  = s.length();
        if(len == 0 || len == 1)return len;
        int ans = 0;
        for(int i = 0;i < len;i++){
            int t = 1;
            HashSet<Character> set = new HashSet<>();
            set.add(s.charAt(i));
            for(int j = i+1;j < len;j++){
                if(!set.add(s.charAt(j))){
                    break;
                }
                t++;
            }
            ans = Math.max(t,ans);
        }
        return ans;
    }
}

class Solution {
    public int lengthOfLongestSubstring(String s) {
        int len  = s.length();
        if(len == 0 || len == 1)return len;
        int ans = 0;
        int left = 0;
        HashMap<Character,Integer> map = new HashMap<>();
        for(int i = 0;i < len;i++){
            if(map.containsKey(s.charAt(i))){
                left = Math.max(left,map.get(s.charAt(i))+1);
            }
            map.put(s.charAt(i),i);
            ans = Math.max(ans,i-left+1);
        }
        return ans;
    }
}

class Solution {
    public int longestConsecutive(int[] nums) {
        int len = nums.length;
        if(len <= 1)return len;
        HashSet<Integer> set = new HashSet<>();
        for(int i = 0;i < len;i++){
            set.add(nums[i]);
        }
        int res = 0;
        for(int i = 0;i < len;i++){
            if(!set.contains(nums[i]-1)){
                int curNum = nums[i];;
                int t = 1;
                while(set.contains(curNum+1)){
                    t++;
                    curNum++;
                }
                res = Math.max(res,t);
            }
        }
        return res;
    }
}

class Solution {
    public List<Integer> findAnagrams(String s, String p) {
        int slen = s.length();
        int plen = p.length();
        List<Integer> list = new ArrayList<>();
        if(slen < plen) return list;
        int []parr = new int[26];
        int []sarr = new int[26];
        for(int i = 0;i < plen;i++){
            parr[p.charAt(i)-'a']++;
            sarr[s.charAt(i)-'a']++;
        }
        if(Arrays.equals(sarr,parr)){
            list.add(0);
        }
        for(int i = 1;i <= slen-plen;i++){
            sarr[s.charAt(i-1)-'a']--;
            sarr[s.charAt(i+plen-1)-'a']++;
            if(Arrays.equals(sarr,parr)){
                list.add(i);
            }
        }
        return list;
    }
}