B. Powers of Two You are given n integers a1, a2, ..., an. Find the number of pairs of indexes i, j (i < j) that ai + aj is a power of 2 (i. e. some integer xexists so that ai + aj = 2x). Input The first line contains the single positive integer n
1.输入姓名直到输入的是quit时(不区分大小写),停止输入然后显示出输入的姓名个数及姓名: 要求结果如下图所示: class Program { static void Main(string[] args) { //集合存放输入的姓名 List<string> listName = new List<string>(); //记录输入的姓名个数 ; ; while (true) { Console.WriteLine("请输入姓名:"); string in
Given a list of numbers, find the number of tuples of size N that add to S. for example in the list (10,5,-1,3,4,-6), the tuple of size 4 (-1,3,4,-6) adds to 0. 题目: 给一数组,求数组中和为S的N个数 思路: 回溯法,数组中每个数都有两种选择,取或者不取: 当选择的数等于N时,则判断该数之和是否等于S. 代码: #include <io
unsigned int str_num(char *str[], int num[], int len) { int i, j; int count; int flag[len]; ; i < len; i++) { num[i] = ; flag[i] = ; } ; i < len; i ++) { ; j <= len; j ++) { == flag[i])&& ( == strncmp(str[j], str[i], strlen(str[j]) > s