随笔分类 - LeetCode
摘要：思路：使用两个指针p1和p2遍历链表，p1在前p2在后。若p1指向的值小于p2指向的值，则p2向前走，直到二者不相等，然后更改p1的指针，再将p1和p2都向前走一步，这么做直到p2到达链表尾部。
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摘要：class Solution { public: int searchInsert(vector& nums, int target) { int len=nums.size(); if(len nums[mid]) low=mid+1; else high=mid...
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摘要：题目描述： 思路1： 利用动态规划。由于空间复杂度的限制，直接在triangle数组上进行修改，即把triangle数组当作dp数组。当j == 0时（即每一行的第一个元素），triangle[i][j] += triangle[i - 1][j]；当j == col - 1时（即每一行的最后一个元
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摘要：题目描述：给定一个整形数组，数组是升序排列的，可能存在负数，统计数组中所有不同绝对值的元素的个数。 思路：设置两个指针，分别指向数组的第一个元素和最后一个元素，可以看做是两个有序数组的合并过程（从大到小合并）。
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摘要：557. Reverse Words in a String III 557. Reverse Words in a String III Given a string, you need to reverse the order of characters in each word within
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摘要：96. Unique Binary Search Trees Given n, how many structurally unique BST's (binary search trees) that store values 1...n? For example, Given n = 3, th
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摘要：530. Minimum Absolute Difference in BST Given a binary search tree with non-negative values, find the minimum absolute difference between values of an
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摘要：520. Detect Capital Given a word, you need to judge whether the usage of capitals in it is right or not. We define the usage of capitals in a word to
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摘要：leetcode 105题，由树的前序序列和中序序列构建树结构。详细解答参考《剑指offer》page56. 先序遍历结果的第一个节点为根节点，在中序遍历结果中找到根节点的位置。然后就可以将问题拆分，递归求解。
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摘要：递归方法： 非递归：要借助栈，可以利用C++ STL中的stack。首先将根节点压栈，然后压入栈顶元素的左节点直到叶子节点，然后访问叶子节点后压入该节点的右子节点。
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摘要：437. Path Sum III You are given a binary tree in which each node contains an integer value. Find the number of paths that sum to a given value. The pa
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摘要：500. Keyboard Row Given a List of words, return the words that can be typed using letters of alphabet on only one row's of American keyboard like the
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摘要：504. Base 7 Given an integer, return its base 7 string representation. Example 1: Input: 100 Output: "202" Example 2: Input: -7 Output: "-10" Note: Th
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摘要：28. Implement strStr() Implement strStr(). Returns the index of the first occurrence of needle in haystack, or -1 if needle is not part of haystack. 思
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摘要：70. Climbing Stairs You are climbing a stair case. It takes n steps to reach to the top. Each time you can either climb 1 or 2 steps. In how many dist
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摘要：459. Repeated Substring Pattern Given a non-empty string check if it can be constructed by taking a substring of it and appending multiple copies of t
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摘要：53. Maximum Subarray Find the contiguous subarray within an array (containing at least one number) which has the largest sum. For example, given the a
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摘要：326. Power of Three Given an integer, write a function to determine if it is a power of three. Follow up: Could you do it without using any loop / rec
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摘要：Write an algorithm to determine if a number is "happy". A happy number is a number defined by the following process: Starting with any positive intege
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摘要：405. Convert a Number to Hexadecimal Given an integer, write an algorithm to convert it to hexadecimal. For negative integer, two’s complement method
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