Given a non-empty array of integers, return the k most frequent elements.
Example 1:
Input: nums = [1,1,1,2,2,3], k = 2
Output: [1,2]
Example 2:
Input: nums = [1], k = 1
Output: [1]
Note:
算法复杂度不符合要求
public List<Integer> topKFrequent(int[] nums, int k) {//排序 map my
List<Integer> res = new ArrayList<Integer>();
Map<Integer,Integer> map=new HashMap<Integer,Integer>();
for (int i = 0; i < nums.length; i++) {
if(map.containsKey(nums[i])){
map.put(nums[i],map.get(nums[i])+1);
}
else{
map.put(nums[i],1);
}
}
for (int i = 0; i <k ; i++) {
int max=0;
int value = 0;
for (Map.Entry entry:map.entrySet()) {
if((Integer)entry.getValue()>max){
max = (Integer)entry.getValue();
value = (Integer)entry.getKey();
}
}
res.add(value);
map.put(value,0);
}
return res;
}
桶排序
堆排序
LeetCode-347. Top K Frequent Elements
原文：https://www.cnblogs.com/zhacai/p/10436261.html