leetcode-java-137. Single Number II

public class Solution {
public int singleNumber(int[] nums) {
Map<Integer,Integer> map = new HashMap<Integer,Integer>();

int len = nums.length,
result = 0,
i = 0;

for(;i < len;i++) {
if(!map.containsKey(nums[i])) {
map.put(nums[i],1);
} else {
int count = map.get(nums[i]);
count++;
map.put(nums[i],count);
}
}

for(Map.Entry<Integer,Integer> entry:map.entrySet()) {
if(entry.getValue() != 3) {
result = entry.getKey();
}
}
return result;
}
}