摘要：链接: https://oj.leetcode.com/problems/maximum-product-subarray/求最大连续序列的乘积因为偶数个负数相乘为正数,且任何数乘0等于0.所以在计算的过程中需要维护两个数组,一个记录到当前位的最大乘积,一个记录到当前位的最小乘积..并初始化为A[i... 阅读全文

摘要：链接: https://oj.leetcode.com/problems/merge-two-sorted-lists/题目要去把两个有序的链表合并,并且合并后的链表依然有序./** * Definition for singly-linked list. * struct ListNode { *... 阅读全文

摘要：链接: https://oj.leetcode.com/problems/single-number-ii/虽然知道这个题肯定跟位运算,异或有关...但实在没想出来怎么解决class Solution {public: int singleNumber(int A[], int n) { ... 阅读全文

摘要：链接: https://oj.leetcode.com/problems/find-peak-element/题目要求复杂度在对数级以内对数组下标进行二分搜索,public class Solution{ public int findPeakElement(int [] num) { int l... 阅读全文

摘要：链接: https://oj.leetcode.com/problems/minimum-path-sum/简单的动态规划.[i][j]表示到达位置(i,j)时的最小sumpublic class Solution{ public int minPathSum(int[][] grid) { in... 阅读全文

摘要：链接: https://oj.leetcode.com/problems/3sum/2sum:尺取法 通过a+b与target比较,.根据大于或小于不断缩小范围3sum:即对0~n个数分别做2sum...去重: if(i!=0&&num[i]==num[i-1]) continue;只有当i=... 阅读全文

摘要：链接: https://oj.leetcode.com/problems/best-time-to-buy-and-sell-stock-ii/class Solution{ public: int maxProfit(vector &prices) { if(prices.size()==... 阅读全文

摘要：链接: https://oj.leetcode.com/problems/permutations/每次从num中选择一个数添加到结果中,并用used标记用过的数.public class Solution { private boolean used[]; private List > ans;... 阅读全文

摘要：链接: https://oj.leetcode.com/problems/rotate-list//** * Definition for singly-linked list. * public class ListNode { * int val; * ListNode next... 阅读全文

摘要：链接: https://oj.leetcode.com/problems/reorder-list/空间复杂度为O(n),时间复杂度为 O(n)的代码:/** * Definition for singly-linked list. * struct ListNode { * int val... 阅读全文

摘要：链接: https://oj.leetcode.com/problems/sum-root-to-leaf-numbers/dfs..sum保存中间结果.每计算完一条路径,就更新ans/** * Definition for binary tree * struct TreeNode { * ... 阅读全文