题目链接:https://leetcode.com/problems/count-numbers-with-unique-digits/题目:
Given a non-negative integer n, count all numbers with unique digits, x, where 0 ≤ x < 10n.Example:
Given n = 2, return 91. (The answer should be the total numbers in the range of 0 ≤ x < 100, excluding [11,22,33,44,55,66,77,88,99])Hint:A direct way is to use the backtracking approach.
Backtracking should contains...
descriptionGiven a positive integer N, return the number of positive integers less than or equal to N that have at least 1 repeated digit.
ExampleInput: 1000
Output: 262
分析这道题目中 testcase 有错误,所以真的不知道哪些 ac 的答案是怎么做到的? 犯错都是犯一样的错误~
count = 0
dup = [‘00‘, ‘11‘, ‘22‘, ‘33‘, ‘44‘, ‘55‘, ‘66‘, ‘77‘, ‘88‘, ‘99‘]for i in range(1, 1001):s = str(i)fo...
descptionWe have a sorted set of digits D, a non-empty subset of {‘1‘,‘2‘,‘3‘,‘4‘,‘5‘,‘6‘,‘7‘,‘8‘,‘9‘}. (Note that ‘0‘ is not included.)Now, we write numbers using these digits, using each digit as many times as we want. For example, if D = {‘1‘,‘3‘,‘5‘}, we may write numbers such as ‘13‘, ‘551‘, ‘1351315‘.Return the number of positive integers that can be written...
Given a non-negative integer N, find the largest number that is less than or equal to N with monotone increasing digits.(Recall that an integer has monotone increasing digits if and only if each pair of adjacent digits x and y satisfy x <= y.) Example 1:Input: N = 10
Output: 9
Example 2:Input: N = 1234
Output: 1234
Example 3:Input: N = 332
Output: 299
Note: N is an integer in the range [0, 10^9...
题目如下:Given an integer n, count the total number of digit 1 appearing in all non-negative integers less than or equal to n.Example:Input: 13
Output: 6
Explanation: Digit 1 occurred in the following numbers: 1, 10, 11, 12, 13.解题思路:本题是《编程之美》上的题目,详细分析如下图。代码如下:class Solution(object):def countDigitOne(self, n):""":type n: int:rtype: int"""if n <= 0:return 0res = 0sn...
Given a non-negative integer num, repeatedly add all its digits until the result has onlyone digit.
For example:
Given num = 38, the process is like: 3+ 8 = 11, 1 + 1 = 2. Since 2 hasonly one digit, return it.Follow up:
Could you do it without any loop/recursion in O(1) runtime?
题目描述:给出一个数组,不断地分割数字,直到这个数字是一个数字为止。题目很简单,直接上代码。
代码实现:class Solution {
...
1295. Find Numbers with Even Number of Digits(统计位数为偶数的数字)链接https://leetcode-cn.com/problems/find-numbers-with-even-number-of-digits题目给你一个整数数组?nums,请你返回其中位数为?偶数?的数字的个数。示例 1:输入:nums = [12,345,2,6,7896]
输出:2
解释:
12 是 2 位数字(位数为偶数)?
345 是 3 位数字(位数为奇数)??
2 是 1 位数字(位数为奇数)?
6 是 1 位数字 位数为奇数)?
7896 是 4 位数字(...
We have a?sorted?set of digits?D, a non-empty subset of?{‘1‘,‘2‘,‘3‘,‘4‘,‘5‘,‘6‘,‘7‘,‘8‘,‘9‘}.? (Note that?‘0‘?is not included.)Now, we write numbers using these digits, using each digit as many times as we want.? For example, if?D = {‘1‘,‘3‘,‘5‘}, we may write numbers such as?‘13‘, ‘551‘, ‘1351315‘.Return the number of positive integers that can be written (using t...
1class Solution2{3public:4int count(int n, int x)5 {6int cnt = 0, k;7for (int i = 1; k = n / i; i *= 10)8 {9int high = k / 10;
10if (x == 0)
11 {
12if (high)
13 {
14 high--;
15 }
16else17 {
18break;
19 }
20 }
21 cnt += high * i;
22int c...
题目Given an integer n, count the total number of digit 1 appearing in all non-negative integers less than or equal to n.For example:
Given n = 13,
Return 6, because digit 1 occurred in the following numbers: 1, 10, 11, 12, 13.解题思路题目理解:题目的意思是给定一个数n,计算[0, n]的区间中1出现的次数。具体思路:在面试过程中如果被问到类似的题目,一定不要着急,因为这肯定是一道找规律的题目。最好的办法...
Number of Digit OneGiven an integer n, count the total number of digit 1 appearing in all non-negative integers less than or equal to n.For example:Given n = 13,Return 6, because digit 1 occurred in the following numbers: 1, 10, 11, 12, 13. 数学题,真是为难了数学拙计的我了。递归分治,拿8192举栗子:把8192拆成:1-999 -> 递归(999)1000-1999 -> 1000个1 + 递归(999)2001-2999 -> 递归(999)..8000-8192 ->...
Given an integer n, count the total number of digit 1 appearing in all non-negative integers less than or equal to n.For example:Given n = 13,Return 6, because digit 1 occurred in the following numbers: 1, 10, 11, 12, 13.Hint:1. Beware of overflow.解题思路:看得答案。很烧脑,没有看得很明白。这题实际上相当于一道找规律的题。那么为了找出规律,我们就先来列举下所有含1的数字,并每10个统计下个数,如下所示...
Given a non-negative integer num, repeatedly add all its digits until the result has only one digit.For example:Given num = 38, the process is like: 3 + 8 = 11, 1 + 1 = 2. Since 2 has only one digit, return it.这道题是求一个数的数根。数根有一个同余性质:一个数与它的数根对(b-1)同余(b是进制数)。举个简单的例子就明白了:123=1*100+2*10+3=1*(99+1)+2*(9+1)+3=(99+2*9)+(1+2+3)前面一项能被9整除,后面...
Given a non-negative integer num, repeatedly add all its digits until the result has only one digit.For example:Given num = 38, the process is like: 3 + 8 = 11, 1 + 1 = 2. Since 2 has only one digit, return it.Follow up:Could you do it without any loop/recursion in O(1) runtime?题目意思是重复地将一个数字每一位数字加起来得到一个新的数字直到得到一个一位数。如果没有下面的提示O(1),恐怕我也就直接模拟去...
Given an array nums of integers, return how many of them contain an even number of digits. Example 1:Input: nums = [12,345,2,6,7896]Output: 2Explanation: 12 contains 2 digits (even number of digits). 345 contains 3 digits (odd number of digits). 2 contains 1 digit (odd number of digits). 6 contains 1 digit (odd number of digits). 7896 contains 4 digits (even number of digits). Therefore only 12 an...