How to count the occurrences of a number?

Given a sorted array arr[] and a number x, write a function that counts the occurrences of x in arr[]. Expected time complexity is O(Logn) Examples: Input: arr[] = {1, 1, 2, 2, 2, 2, 3,}, x = 2 Output: 4 // x (or 2) occurs 4 times in arr[] Input: arr

count()函数功能:统计表中中某个字段或所有记录个数,字段值为null的不做统计. 手册中解释: COUNT returns the number of rows returned by the query. You can use it as an aggregate or analytic function. If you specify DISTINCT, then you can specify only the query_partition_clause of the analy

Description You are working for Macrohard company in data structures department. After failing your previous task about key insertion you were asked to write a new data structure that would be able to return quickly k-th order statistics in the array

看上去像是回文串自动机的模板题,就来了一发 The Number of Palindromes Time Limit: 6000/3000 MS (Java/Others)    Memory Limit: 262144/262144 K (Java/Others) Total Submission(s): 1992    Accepted Submission(s): 694 Problem Description Now, you are given a string S. We want

Given an integer, write an algorithm to convert it to hexadecimal. For negative integer, two’s complementmethod is used. Note: All letters in hexadecimal (a-f) must be in lowercase. The hexadecimal string must not contain extra leading 0s. If the num

在一个数组中找到主要的元素,也就是出现次数大于数组长度一半的元素. 我想到的方法是 1. 排序,然后扫描一次就知道了.总共nlgn 2. 哈希,记录每个次数,O(n)的时间和空间. class Solution { public: int majorityElement(vector<int> &num) { unordered_map<int, int> umap; for (int i = 0; i < num.size(); i++) { umap[num[i]

你会写注释么?从我写代码开始,这个问题就一直困扰着我,相信也同样困扰着其他同学.以前的写注释总是没有一套行之有效的标准,给维护和协同开发带了许多麻烦,直到最近读到了phpdocumentor的注释标准. 下面对phpdocumentor的注释标准进行总结: Type(数据类型): string 字符串类型 integer or int 整型 boolean or bool 布尔类型 true or false float or double 浮点类型 object 对象 mixed 混合类型 没

Problem Statement Given a large array of non-negative integer numbers, write a function which determines whether or not there is a number that appears in the array more times than all other numbers combined. If such element exists, function should re

1 #include<iostream> 2 #include<ctime> 3 #include <stdio.h> 4 #include<cstring> 5 #include<cstdlib> 6 #include <map> 7 #include <string> 8 using namespace std; 9 // A utility function to get maximum value in arr[]