题目: Given a string S and a string T, count the number of distinct subsequences of T in S. A subsequence of a string is a new string which is formed from the original string by deleting some (can be none) of the characters without disturbing the relat…
题目: Follow up for N-Queens problem. Now, instead outputting board configurations, return the total number of distinct solutions. 代码: class Solution { public: int totalNQueens(int n) { ; ) return ret; vector<*n-,*n-,false); Solution::dfs(ret, , n, col…
题目: 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 distinct ways can you climb to the top? 代码: class Solution { public: int climbStairs(int n) { ; ; ; i<n; ++i) { const in…
题目: Determine if a Sudoku is valid, according to: Sudoku Puzzles - The Rules. The Sudoku board could be partially filled, where empty cells are filled with the character '.'. A partially filled sudoku which is valid. Note:A valid Sudoku board (partia…
题目: Given a collection of numbers that might contain duplicates, return all possible unique permutations. For example,[1,1,2] have the following unique permutations:[1,1,2], [1,2,1], and [2,1,1]. 代码: class Solution { public: vector<vector<int>>…
题目: Given a collection of integers that might contain duplicates, nums, return all possible subsets. Note: Elements in a subset must be in non-descending order. The solution set must not contain duplicate subsets. For example,If nums = [1,2,2], a sol…
题目: Given an array with n objects colored red, white or blue, sort them so that objects of the same color are adjacent, with the colors in the order red, white and blue. Here, we will use the integers 0, 1, and 2 to represent the color red, white, an…
