LeetCode - 随笔分类 - canexjtuzju

LeetCode-- Unique Binary Search Trees II

摘要：递归 1 /** 2 * Definition for binary tree 3 * struct TreeNode { 4 * int val; 5 * TreeNode *left; 6 * TreeNode *right; 7 * TreeNode... 阅读全文

posted @ 2014-09-12 10:03 canexjtuzju 阅读(133) 评论(0) 推荐(0)

LeetCode--Next Permutation

摘要：（1）从后往前，找到a[i] &num) { 4 int end = num.size() - 1; 5 int povit = end; 6 while(povit > 0){ 7 if(num[povit] > num[po... 阅读全文

posted @ 2014-09-10 21:01 canexjtuzju 阅读(208) 评论(0) 推荐(0)

LeetCode--Wrod Break

摘要：---恢复内容开始--- 1 class Solution { 2 public: 3 bool wordBreak(string s, unordered_set &dict) { 4 int nsize=s.size(); 5 int i=0,j=0; 6... 阅读全文

posted @ 2014-09-08 21:14 canexjtuzju 阅读(131) 评论(0) 推荐(0)

LeetCode--Largest Rectangle in Histogram

摘要：---恢复内容开始--- 1 class Solution { 2 public: 3 int largestRectangleArea(vector &height) { 4 int n = height.size(); 5 if(n == 0) 6 ... 阅读全文

posted @ 2014-09-08 20:56 canexjtuzju 阅读(129) 评论(0) 推荐(0)

LeetCode--Binary Tree Maximum Path Sum

摘要：递归，dfs这里返回值是一个pair，first表示两个子树的不经过当前root的最大pathsum；second表示两个子树的，以root->left和root->right为路径起始节点的路径的最大值 1 /** 2 * Definition for binary tree 3 * stru... 阅读全文

posted @ 2014-09-07 18:55 canexjtuzju 阅读(144) 评论(0) 推荐(0)

LeetCode--Reorder List

摘要：（1）双指针（快慢）：找到中节点（2）反转第一或者第二个链表（反转第一个后面合并完了还得再反转），所以建议反转第二个链表代码：暂时不贴了https://oj.leetcode.com/problems/reorder-list/ 阅读全文

posted @ 2014-09-07 15:34 canexjtuzju 阅读(127) 评论(0) 推荐(0)

LeetCode--Combination Sum

摘要：由于需要就地保存清零信息，所以把信息保存在第一行和第一列 1 class Solution { 2 public: 3 void setZeroes(vector > &matrix) { 4 const int ROW = matrix.size(); 5 ... 阅读全文

posted @ 2014-09-06 23:31 canexjtuzju 阅读(148) 评论(0) 推荐(0)

LeetCode--Binary Tree Level Order Traversal

摘要：用两个队列实现，交叉使用，达到判断层的目的 1 /** 2 * Definition for binary tree 3 * struct TreeNode { 4 * int val; 5 * TreeNode *left; 6 * TreeNode *right... 阅读全文

posted @ 2014-09-06 23:17 canexjtuzju 阅读(151) 评论(0) 推荐(0)

LeetCode--Plus One

摘要：考查，最高位有进位 1 class Solution { 2 public: 3 vector plusOne(vector &digits) { 4 // IMPORTANT: Please reset any member data you declared, as 5 ... 阅读全文

posted @ 2014-09-04 22:33 canexjtuzju 阅读(131) 评论(0) 推荐(0)

LeetCode--Combination Sum

摘要：一开始的思路是：中序遍历+判断遍历后的数组，时间空间都不是最优果然超时了 1 /** 2 * Definition for binary tree 3 * struct TreeNode { 4 * int val; 5 * TreeNode *left; 6 * ... 阅读全文

posted @ 2014-09-04 22:10 canexjtuzju 阅读(171) 评论(0) 推荐(0)

LeetCode--Balanced Binary Tree

摘要：递归 1 /** 2 * Definition for binary tree 3 * struct TreeNode { 4 * int val; 5 * TreeNode *left; 6 * TreeNode *right; 7 * TreeNode... 阅读全文

posted @ 2014-09-04 21:16 canexjtuzju 阅读(143) 评论(0) 推荐(0)

LeetCode--N-Queens II

摘要：dfs 1 class Solution { 2 public: 3 int res; 4 int totalNQueens(int n) { 5 res = 0; 6 vector arr(n); 7 dfs(arr,0,n); 8 ... 阅读全文

posted @ 2014-09-04 21:07 canexjtuzju 阅读(131) 评论(0) 推荐(0)

LeetCode--Merge Two Sorted Lists

摘要：重新写了下，代码看着清爽多了 1 /** 2 * Definition for singly-linked list. 3 * struct ListNode { 4 * int val; 5 * ListNode *next; 6 * ListNode(int x... 阅读全文

posted @ 2014-09-04 20:20 canexjtuzju 阅读(155) 评论(0) 推荐(0)

LeetCode--Restore IP Addresses

摘要：dfs即可注意边界情况：（1）s长度不在4 和 12之间（2）"010"这种形式是错误的 1 class Solution { 2 public: 3 vector restoreIpAddresses(string s) { 4 vector res; 5 ... 阅读全文

posted @ 2014-09-04 10:13 canexjtuzju 阅读(148) 评论(0) 推荐(0)

LeetCode--3Sum

摘要：类似于2sum，先排序，然后从左开始遍历，计算a[i]后面的等于-a[i]的两个元素，注意去除重复元素 1 class Solution { 2 public: 3 vector > threeSum(vector &num) { 4 vector > res; 5 ... 阅读全文

posted @ 2014-08-30 22:39 canexjtuzju 阅读(147) 评论(0) 推荐(0)

LeetCode--Insert Interval

摘要：其实可以O（n）的思路，如下 1 class Solution { 2 public: 3 vector insert(vector &intervals, Interval newInterval) { 4 // Start typing your C/C++ soluti... 阅读全文

posted @ 2014-08-27 21:41 canexjtuzju 阅读(228) 评论(0) 推荐(0)

LeetCode--Surrounded Regions

摘要：1 class Solution { 2 public: 3 void solve(vector> &board) { 4 int m = board.size(); 5 if(m == 0) 6 return; 7 ... 阅读全文

posted @ 2014-08-27 21:06 canexjtuzju 阅读(166) 评论(0) 推荐(0)

LeetCode--Container With Most Water

摘要：双指针 1 class Solution { 2 public: 3 int maxArea(vector &height) { 4 if(height.size() == 0 || height.size() == 1) 5 return 0; 6 ... 阅读全文

posted @ 2014-08-27 09:51 canexjtuzju 阅读(140) 评论(0) 推荐(0)

LeetCode--Permutation Sequence

摘要：1 class Solution { 2 public: 3 string getPermutation(int n, int k) { 4 int fac[10]; 5 bool vis[10]; 6 memset(vis, 0, size... 阅读全文

posted @ 2014-08-25 14:06 canexjtuzju 阅读(128) 评论(0) 推荐(0)

LeetCode--Regular Expression Matching

摘要：1 class Solution { 2 public: 3 bool isMatch(const char *s, const char *p) { 4 // Start typing your C/C++ solution below 5 // DO N... 阅读全文

posted @ 2014-08-25 12:46 canexjtuzju 阅读(162) 评论(0) 推荐(0)

随笔分类 - LeetCode