packageeasy;

publicclassCompareVersionNumbers {

publicstaticintcompareVersion(Stringversion1,Stringversion2) {

String[]v1s =version1.split("\\.");//escaping it is very important! Otherwise, it's not going to work as expected!

String[]v2s =version2.split("\\.");

intlen = (v1s.length <v2s.length) ?v2s.length :v1s.length;

for(inti =0;i <len;i++){

if(v1s.length ==i){

while(i <len){

if(Integer.parseInt(v2s[i]) >0)return -1;

i++;

}

}elseif(v2s.length ==i){

while(i <len){

if(Integer.parseInt(v1s[i]) >0)return1;

i++;

}

}else {

if(Integer.parseInt(v1s[i]) >Integer.parseInt(v2s[i]))return1;

elseif(Integer.parseInt(v2s[i]) >Integer.parseInt(v1s[i]))return -1;

elsecontinue;//this line is not necessary, but just to make the logic more clear

}

}

return0;

}

publicstaticvoidmain(String...args){

Stringversion1 ="1.0";

Stringversion2 ="1";//should return 0

System.out.println(compareVersion(version1,version2));

}

}

|189|[Rotate Array](https://leetcode.com/problems/rotate-array/)|[Solution](../../blob/master/EASY/src/easy/RotateArray.java)| O(n)|O(n), could be optimized to O(1) | Easy

|173|[Binary Search Tree Iterator](https://leetcode.com/problems/binary-search-tree-iterator/)|[Queue](../../blob/master/MEDIUM/src/medium/BSTIterator_using_q.java)[Stack](../../blob/master/MEDIUM/src/medium/BSTIterator_using_stack.java)| O(1)|O(h)| Medium|

|172|[Factorial Trailing Zeroes](https://leetcode.com/problems/factorial-trailing-zeroes/)|[Solution](../../blob/master/EASY/src/easy/FactorialTrailingZeroes.java)| O(logn)|O(1)| Easy

|165|[Compare Version Numbers](https://leetcode.com/problems/compare-version-numbers/)|[Solution](../../blob/master/EASY/src/easy/CompareVersionNumbers.java)| O(n)|O(1)| Easy|

|162|[Find Peak Element](https://leetcode.com/problems/find-peak-element/)|[Solution](../../blob/master/MEDIUM/src/medium/FindPeakElement.java)| O(1)|O(logn)/O(n)| Binary Search|

|155|[Min Stack](https://leetcode.com/problems/min-stack/)|[Solution](../../blob/master/EASY/src/easy/MinStack.java)| O(1)|O(n) | Easy| Stack

|140|[Word Break II](https://leetcode.com/problems/word-break-ii/)|[Solution](../../blob/master/HARD/src/hard/WordBreakII.java)| ? |O(n^2) | Hard| Backtracking/DFS