Nightmare_ak的博客

马拉车求最长回文子串class Solution { const static int N=1e5+5; char ss[N]; int L[N];public: string longestPalindrome(string s) { int len=0; ss[len++]='$'; for(int i=0;i...

class Solution {public: int longestValidParentheses(string s) { stack<int> stk; vector<int> num(s.size(),0); int mxx=0; for(int i=0;i<s.size();++i){...

class Solution {public: void nextPermutation(vector<int>& nums) { int p=-1; for(int i=(int)nums.size()-2;i>=0;i--){ if(nums[i]<nums[i+1]){ ...

双指针class Solution {public: vector<int> findSubstring(string s, vector<string>& words) { if(s==""||!words.size()) return vector<int>(); unordered_map<stri...

枚举每个符号作为中间符号，递归计算两边所有可能，组合在一起即可class Solution {public: vector&lt;int&gt; num; vector&lt;char&gt; op; vector&lt;int&gt; dfs(int l,int r) { if(l==r) return {num[l/2]}; ...

链表，参考标解，非常巧妙/** * Definition for singly-linked list. * struct ListNode { * int val; * ListNode *next; * ListNode(int x) : val(x), next(NULL) {} * }; */class Solution {public: ...

思路和上上题一致，复杂度O(n3)O(n^3)O(n3)class Solution {public: vector&lt;vector&lt;int&gt;&gt; fourSum(vector&lt;int&gt;&amp; nums, int target) { sort(nums.begin(),nums.end()); vector&lt;ve...

思路与上一题一致，每次都为达到targettargettarget而l++l++l++或r−−r--r−−，在过程中记录差值最小的值即可，复杂度O(N2)O(N^2)O(N2)class Solution {public: int threeSumClosest(vector&amp;lt;int&amp;gt;&amp;amp; nums, int target) { sort(nums.b...

双指针维护，2都往右放，0都往左放class Solution {public: void sortColors(vector&lt;int&gt;&amp; nums) { int n=nums.size(); int l=0,r=n-1; for(int i=0;i&lt;n;i++) { wh...

分别写了堆排序和快速排序class Solution {public: int findKthLargest(vector&lt;int&gt;&amp; nums, int k) { int n=nums.size(); auto modify=[&amp;](int l,int r) { while(2*l+1&...

二分，为了不使用long long，过程中需要一些技巧class Solution {public: int mySqrt(int x) { if(x&lt;=1) return x; int l=0,r=x; while(l&lt;=r) { int m=(l+r)&gt;&gt;1; ...

标解O(n2)O(n^2)O(n2)，我的方法看上去是O(n2logn)O(n^2logn)O(n2logn)class Solution {public: struct Tuple { int a,b,c; bool operator&lt;(const Tuple&amp;t)const { if(a!...

标解O(n)，开了题解才明白。。。自己的方法是O(nlogn)的，从大到小枚举，二分+树状数组得到最小或最大的下标。class Solution{public: int maxArea(vector&amp;lt;int&amp;gt;&amp;amp; height) { int n=height.size(); int l=0,r=n-1,mxx=0; ...

区间dp，虽然AC了，但是有个疑问abc和.**我觉得是YES吧，标程输出NO，可能题目不考虑多个*的情况吧。class Solution {public: bool isMatch(string s, string p) { int n=s.length(),m=p.length(); vector&lt; vector&lt;bool&gt; &gt...

sscanf()的使用class Solution {public: typedef long long ll; int myAtoi(string str) { ll x=0; sscanf(str.c_str(),"%lld",&amp;x); if(x&lt;-(1LL&lt;&lt;31)) x=-(1LL&lt;&lt;...

简单的题目反而坑点多啊，用long long防止溢出class Solution {public: typedef long long ll; int reverse(int x) { int f=1; ll xx=x; if(x&lt;0) f=-1,xx=-xx; ll ans=0; while...

class Solution {public: string convert(string s, int numRows) { int len=s.size(); int x=1,dirx=0; string v[numRows+1]; for(int i=0;i&amp;lt;len;i++) { ...

class Solution {public: int search(vector<int>& nums, int target) { int l=0,r=nums.size(); while(l<r){ int m=l+r>>1; if(target==nums[m])...