|4|[Median of Two Sorted Arrays](https://leetcode.com/problems/median-of-two-sorted-arrays/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_4.java) | ? | ? | Hard | Divide and Conquer

|3|[Longest Substring Without Repeating Characters](https://leetcode.com/problems/longest-substring-without-repeating-characters/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_3.java) | O(n) | O(1) | Medium | HashMap, Sliding Window

|2|[Add Two Numbers](https://leetcode.com/problems/add-two-numbers/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_2.java) | O(max(m,n)) | O(1) | Medium | LinkedList

|1|[Two Sum](https://leetcode.com/problems/two-sum/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1.java)| O(n)/O(n^2)|O(1)/O(n) | Easy| HashMap

|1|[Two Sum](https://leetcode.com/problems/two-sum/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1.java)| O(n)|O(n) | Easy| HashMap

publicclass_1 {

publicint[]twoSum_ON(int[]nums,inttarget) {

publicint[]twoSum(int[]nums,inttarget) {

Map<Integer,Integer>map =newHashMap();

int[]result =newint[2];

for(inti =0;i <nums.length;i++){

returnresult;

}

publicint[]twoSum_ON2(int[]nums,inttarget) {

int[]result =newint[2];

for(inti =0;i <nums.length-1;i++){

for(intj =i+1;j <nums.length;j++){

if(nums[i] +nums[j] ==target){

result[0] =i;

result[1] =j;

break;

}

}

}

returnresult;

}

}