哈希·数学模式

整数转罗马数字

Convert a given integer to its Roman numeral representation using hash table mapping and decimal place math operations e…

罗马数字转整数

Convert a Roman numeral string into an integer using a hash table and mathematical principles to determine value order.

分数到小数

Convert a fraction into a decimal, handling repeating decimals with parentheses around the repeating part.

随机数索引

Random Pick Index involves selecting a random index of a target number in an array with possible duplicates.

从英文中重建数字

This problem asks you to reconstruct digits from an out-of-order English string using hash counting and mathematical ded…

随机翻转矩阵

Design an optimized algorithm to randomly flip an index in a matrix, using hash tables and math for efficient random sel…

重新排序得到 2 的幂

Determine if a number's digits can be rearranged to form a power of two using counting and hash-based checks.

强整数

Find all integers that can be expressed as x^i + y^j up to a given bound using a Hash Table plus Math approach.

可被 K 整除的最小整数

Find the length of the smallest positive integer divisible by k that consists only of the digit '1'.

统计最大组的数目

Count the number of groups with the largest size by summing digits of numbers from 1 to n using a hash table approach.

盒子中小球的最大数量

The problem asks you to find the box with the maximum number of balls based on the sum of digits of ball numbers.

统计同位异构字符串数目

Learn to count distinct anagrams for a multi-word string using hash tables, math, and combinatorics efficiently.

判断一个数是否迷人

Determine if a 3-digit number is fascinating by checking if the concatenated result of n, 2*n, and 3*n contains all digi…

统计美丽子字符串 I

Given a string and a value k, count the number of beautiful substrings where vowels * consonants % k == 0.

统计美丽子字符串 II

Count Beautiful Substrings II focuses on finding beautiful substrings with hash tables and number theory techniques.

统计好整数的数目

Count good integers by rearranging digits to form k-palindromic numbers, leveraging hash tables and math techniques.

K 次修改后的最大曼哈顿距离

Solve Maximum Manhattan Distance After K Changes by scanning prefixes and testing the four diagonal target pairs with li…

最小回文排列 II

Find the k-th lexicographically smallest palindromic rearrangement of a given palindromic string s.

最大质数子字符串之和

Compute the sum of the three largest unique primes from all substrings using hash table plus math efficiently.