喵星人与汪星人

摘要： PermutationsGiven a collection of numbers, return all possible permutations.For example,[1,2,3]have the following permutations:[1,2,3],[1,3,2],[2,1,3]... 阅读全文

摘要： CombinationsGiven two integersnandk, return all possible combinations ofknumbers out of 1 ...n.For example,Ifn= 4 andk= 2, a solution is:[ [2,4], [3... 阅读全文

摘要： TriangleGiven a triangle, find the minimum path sum from top to bottom. Each step you may move to adjacent numbers on the row below.For example, given... 阅读全文

摘要： Pascal's Triangle IIGiven an indexk, return thekthrow of the Pascal's triangle.For example, givenk= 3,Return[1,3,3,1].Note:Could you optimize your alg... 阅读全文

摘要： Pascal's TriangleGivennumRows, generate the firstnumRowsof Pascal's triangle.For example, givennumRows= 5,Return[ [1], [1,1], [1,2,1], [1,3,... 阅读全文

摘要： Remove Duplicates from Sorted Array IIFollow up for "Remove Duplicates":What if duplicates are allowed at mosttwice?For example,Given sorted array A =... 阅读全文

摘要： Remove Duplicates from Sorted ArrayGiven a sorted array, remove the duplicates in place such that each element appear onlyonceand return the new lengt... 阅读全文

摘要： Remove ElementGiven an array and a value, remove all instances of that value in place and return the new length.The order of elements can be changed. ... 阅读全文

摘要： Sort ListSort a linked list inO(nlogn) time using constant space complexity.算法思想：时间复杂度为O(nlogn)的排序算法，有快排、归并、堆排序，快排需要往前遍历，因此不适合单链表，堆排序可以，但是需要O(n)的空间，因此... 阅读全文

摘要： Reverse Linked List IIReverse a linked list from positionmton. Do it in-place and in one-pass.For example:Given1->2->3->4->5->NULL,m= 2 andn= 4,return... 阅读全文