两个数组的交集2

Posted 2022-01-31 Alice_yufeng

class Solution 
public int[] intersect(int[] nums1, int[] nums2) 
        int n1 = nums1.length;
        int n2 = nums2.length;
        int n = Math.min(n1,n2);
        int[] arr = new int[n];
        Map<Integer,Integer> map = new HashMap<>();
        for(int i = 0; i < n1; i++)
            if(!map.containsKey(nums1[i]))
                map.put(nums1[i],1);
            else
                map.put(nums1[i],map.get(nums1[i])+1);
            
        
        int k = 0;
        for(int j = 0; j < n2; j++)
            if(map.containsKey(nums2[j]))
                arr[k] = nums2[j];
                k++;
                int x = map.get(nums2[j]) - 1;
                if(x != 0)
                    map.put(nums2[j],x);
                else
                    map.remove(nums2[j]);
                

            
        
        int[] res = new int[k];
        for(int i = 0; i < k; i++)
            res[i] = arr[i];
        
        return res;