dyllanzhou的专栏

Implement int sqrt(int x).Compute and return the square root of x.class Solution {public: /*algorithm: binary search use x/m < m instead of x < m*m to prevent overflow */ int

Given an integer, write a function to determine if it is a power of three.Follow up:Could you do it without using any loop / recursion?Credits:Special thanks to @dietpepsi for adding this pr

Given an integer (signed 32 bits), write a function to check whether it is a power of 4.Example:Given num = 16, return true.Given num = 5, return false.Follow up: Could you solve it without loop

Divide two integers without using multiplication, division and mod operator.If it is overflow, return MAX_INT.class Solution {public: /*algorithm binary search */ int bSearch(lon

Given two numbers represented as strings, return multiplication of the numbers as a string.Note: The numbers can be arbitrarily large and are non-negative.class Solution {public: /*algorithm

Given a positive integer n, find the least number of perfect square numbers (for example,1, 4, 9, 16, ...) which sum to n.For example, given n = 12, return 3 because12 = 4 + 4 + 4; given n = 13,

Given an array containing n distinct numbers taken from 0, 1, 2, ..., n, find the one that is missing from the array.For example,Given nums = [0, 1, 3] return 2.Note:Your algorithm should run

Given an integer, convert it to a roman numeral.Input is guaranteed to be within the range from 1 to 3999./*roman background Symbol     Value I     1 V     5 X     10 L     50 C   

Implement pow(x, n).Have you met this question in a real interview?class Solution {public: /*algorithm: divde and conqure */ double myPow(double x,

Write a program to find the n-th ugly number.Ugly numbers are positive numbers whose prime factors only include 2, 3, 5. For example,1, 2, 3, 4, 5, 6, 8, 9, 10, 12 is the sequence of the first 10

The set [1,2,3,…,n] contains a total of n! unique permutations.By listing and labeling all of the permutations in order,We get the following sequence (ie, for n = 3):"123""132""213""231""312""

Write a program to check whether a given number is an ugly number.Ugly numbers are positive numbers whose prime factors only include 2, 3, 5. For example,6, 8 are ugly while 14 is not ugly since i

Given a non-negative integer n, count all numbers with unique digits, x, where 0 ≤ x n.Example:Given n = 2, return 91. (The answer should be the total numbers in the range of 0 ≤ x < 100, excludin