Header Ad

Leetcode Majority Element II problem solution

In this Leetcode Majority Element II problem solution, you are given an integer array of size n, find all elements that appear more than ⌊ n/3 ⌋ times.

Leetcode Majority Element II problem solution


Problem solution in Python.

import collections
class Solution:
    def majorityElement(self, nums):
        length = len(nums)
        counter = collections.Counter(nums)
        
        if length<3:
            return counter.keys()
        
        result = []
        
        words = counter.most_common(3)
        
        for i in range(0,min(3,len(counter))):
            if words[i][-1]>length/3:
                result.append(words[i][0])
        return result



Problem solution in Java.

public List<Integer> majorityElement(int[] nums) {
    List<Integer> result = new ArrayList<>();
    if(nums.length < 3){
        int n = nums.length;
        for(int i=0; i<n; i++){
            if(!result.contains(nums[i]))
                result.add(nums[i]);
        }
        return result;
    }
        
    Arrays.sort(nums);
    int count=1;
    int gt = nums.length/3;
    for(int i=0; i<nums.length-1; i++){
        if(nums[i] == nums[i+1]){
            count++;
        }
        if(count > 1 && nums[i] != nums[i+1]){ 
            count = 1;
        }
        if(count >= gt+1){
                if(!result.contains(nums[i])){
                    result.add(nums[i]);
                    count = 1;
                }
            }
    }
return result;
}


Problem solution in C++.

vector<int> majorityElement(vector<int>& nums) {
        vector<int> vec;
        int n= floor(nums.size()/3)+1;
        map<int,int> mp;
        map<int,int>::iterator it;    
        for(int i=0;i<nums.size();i++){
            it=mp.find(nums[i]);
            if(it==mp.end())        
                mp.insert(pair<int,int>(nums[i],1));        
            else it->second=mp[nums[i]]+1;        
        } 
        for(it=mp.begin();it!=mp.end();it++){
            if(it->second>=n)        
                vec.push_back(it->first);        
        }
        return vec;   
    }


Problem solution in C.

void add_back(int **ret, int *rS, int num){
    *ret = realloc(*ret, sizeof(int) * (*rS + 1));
    (*ret)[*rS] = num;
    *rS += 1;
    return;
}

int* majorityElement(int* nums, int numsSize, int* returnSize){
    *returnSize = 0;
    if(nums == NULL || numsSize < 1)
        return NULL;
    
   int cand1, cand2, count1, count2;
   cand1 = cand2 = count1 = count2 = 0;
   for (int i = 0; i < numsSize; i++) {
      int num = nums[i];
       if (cand1 == num) {
         count1++;   
       }else if (cand2 == num) {
         count2++;   
       }else if (count1 == 0) {
         cand1 = num;
         count1++;  
       }else if (count2 == 0) {
         cand2 = num;
         count2++;  
       }else {
         count1--;
         count2--;
      }
   }
   
   count1 = count2 = 0;
   for (int i = 0; i < numsSize; i++) {
      int num = nums[i];
      if (cand1 == num)
         count1++;
      else if (cand2 == num)
         count2++;
   }
   int *ret = NULL;

   if(count1 > numsSize/3)
      add_back(&ret, returnSize, cand1);
   
   if(count2 > numsSize/3)
      add_back(&ret, returnSize, cand2); 

   return ret;
}


Post a Comment

0 Comments