代码随想录Day6

lc242

public class lc242 {
    public boolean isAnagram(String s, String t) {
        int [] record=new int[26];
        for (int i = 0; i < s.length(); i++) {
            record[s.charAt(i)-'a']++;
        }

        for (int i = 0; i < t.length(); i++) {
            record[t.charAt(i)-'a']--;
        }

        for (int i = 0; i < record.length; i++) {
            if (record[i]!=0){
                return  false;
            }
        }

        return true;
    }
}

lc349

public class lc349 {
    public int[] intersection(int[] nums1, int[] nums2) {

        HashSet<Integer> hs=new HashSet<>();
        for (int i : nums1) {
            for (int i1 : nums2) {
                if (i==i1){
                    hs.add(i);
                }
            }
        }

        int [] res=new int[hs.size()];
        int index=0;
        for (Integer h : hs) {
           res[index++]=h;
        }
        return  res;

    }
}

lc01

public class lc01 {
    public int[] twoSum(int[] nums, int target) {
        Map<Integer,Integer> hm=new HashMap<>();
        for (int i = 0; i < nums.length; i++) {
            hm.put(nums[i],i);
        }

        for (int i = 0; i < nums.length; i++) {
            int j=target-nums[i];
            if (hm.containsKey(j)&&i!=hm.get(j)){
                return new int []{i,hm.get(j)};
            }
        }

        return null;
    }
}