[LC] Copy List with Random Pointer

Copy List with Random Pointer

Keywords: LinkedList, Careful.

[LC] Valid Palindrome

Valid Palindrome

transform, isalnum.

Keywords: STL.

[LC] Implement strStr()

Implement strStr()

transform.

Keywords: STL.

[LC] String to Integer (atoi)

String to Integer (atoi)

Keywords: Very careful.

[LC] Longest Palindromic Substring

Longest Palindromic Substring

Keywords: DP.

[LC] Wildcard Matching

Wildcard Matching

Keywords: NULL.

[LC] Regular Expression Matching

Regular Expression Matching

Keywords: DFS.

[LC] Longest Common Prefix

Longest Common Prefix

Keywords: NULL.

[LC] Count and Say

Count and Say

bind1st, bind2nd, find_if.

Keywords: STL.

[LC] Rotate List

Rotated List

Keywords: LinkedList.

[LC] Remove Nth Node From End of a List

Remove Nth Node From End of a List

Keywords: LinkedList.

[LC] Remove Duplicates from Sorted List I & II

Remove Duplicates from Sorted List I

Remove Duplicates from Sorted List II

Keywords: LinkedList.

[LC] Partition List

Partition List

Keywords: LinkedList, Careful.

[LC] Reverse Linked List II

Reverse Linked List II

Keywords: LinkedList, Careful.

[LC] Add Two Numbers

Add Two Numbers

Keywords: LinkedList.

[LC] 3Sum, 3Sum Closest, 4Sum

3Sum

Keyword: Binary Search.

3Sum Closest

Keyword: Approaching.

4Sum

Keyword: Hash, Set.

[LC] Longest Consecutive Sequence

Longest Consecutive Sequence

Keyword: Hash.

[LC] Median of Two Sorted Arrays

Median of Two Sorted Arrays

Consider more general case: k-th number of these arrays.

Keyword: Binary Search.

[LC] Search in Rotated Sorted Array I & II

Search in Rotated Sorted Array I


Search in Rotated Sorted Array II

Keyword: Binary Search, Boundary condition.

[LC] Remove Duplicates from Sorted Array I & II

Remove Duplicates from Sorted Array I


Remove Duplicates from Sorted Array II

Add one more variable to record the number of repeated elements.

[LC] Sum Root to Leaf Numbers

Sum Root to Leaf Numbers

Keywords: Top down.

[LC] Binary Tree Maximum Path Sum

Binary Tree Maximum Path Sum

Be careful about the return value of each dfs.

Keywords: DFS.

[LC] Path Sum I & II

Path Sum I & II

Keywords: DFS.

[LC] Unique Binary Search Trees I & II

Unique Binary Search Trees I

Keywords: 1-D dynamic programming.



Unique Binary Search Trees II

Build a function whose input is the range of the subtree and output is the subtrees based on this range.

vector<TreeNode*> generate(int beg, int end){
    /*...*/
    return ans;
}

Keywords: Bottom up.