Given an infinite number of quarters (25 cents), dimes (10 cents), nickels (5 cents) and pennies (1 cent), find how many ways to represent n cents. 思路: 从最大面值的硬币开始分析,然后依次看更小面值的硬币.假设 n = 100, 所有 valid 排列组合中 num_quarters = 0 的是一类, num_quarters = 1 的是一类,…

第18章---高度难题 1,-------另类加法.实现加法. 另类加法 参与人数:327时间限制:3秒空间限制:32768K 算法知识视频讲解 题目描述 请编写一个函数,将两个数字相加.不得使用+或其他算数运算符. 给定两个int A和B.请返回A+B的值 测试样例: 1,2 返回:3 答案和思路:xor是相加不进位.and得到每一个地方的进位.所以,用and<<1之后去与xor异或.不断递归. import java.util.*; public class UnusualAdd { pu…

面试题9.1:有个小孩正在上楼梯,楼梯有n个台阶,小孩一次可以上1阶.2阶或者3阶.实现一个方法,计算小孩有多少种上楼梯的方式. 思路:第4个数是前三个数之和 注意:能不能使用递归,能不能建立一个很大的数组来存储传递的参数(因为可能有空间的限制),要%1000000007防止超出范围 package cc150.recursion_dp; public class GoUpstairs { public static void main(String[] args) { // TODO 自动生成…

You have a total of n coins that you want to form in a staircase shape, where every k-th row must have exactly k coins. Given n, find the total number of full staircase rows that can be formed. n is a non-negative integer and fits within the range of…

You are given coins of different denominations and a total amount of money amount. Write a function to compute the fewest number of coins that you need to make up that amount. If that amount of money cannot be made up by any combination of the coins,…

题目描述 在创立了她们自己的政权之后,奶牛们决定推广新的货币系统.在强烈的叛逆心理的驱使下,她们准备使用奇怪的面值.在传统的货币系统中,硬币的面值通常是1,5,10,20或25,50,以及100单位的货币,有时为了更方便地交易,会发行面值为2单位的硬币. 奶牛们想知道,对于一个给定的货币系统,如果需要正好凑出一定数量的钱,会有多少种不同的方法.比如说,你手上有无限多个面值为{1,2,5,10,...}的硬币,并且打算凑出18单位货币,那么你有多种方法来达到你的目的:18*1,9*2,8*2+2*…

问题:早在ITPUB中看过有个SQL高手,喜欢出谜题,以下是一个谜题.我试用SQL SERVER解决此问题. 用1分,5分,10分,25分,50分硬币凑成一元,总共有几种组合办法? SELECT'1*'+rtrim(a.number) +'+5*'+rtrim(b.number) +'+10*'+rtrim(c.number) +'+25*'+rtrim(d.number) +'+50*'+rtrim(e.number)AS result )a ,()b ,()c ,()d ,()e WHERE…

题目描述 Farmer John's cows like to play coin games so FJ has invented with a new two-player coin game called Xoinc for them. Initially a stack of N (5 <= N <= 2,000) coins sits on the ground; coin i from the top has integer value C_i (1 <= C_i <=…

题目描述 Farmer John's cows like to play coin games so FJ has invented with a new two-player coin game called Xoinc for them. Initially a stack of N (5 <= N <= 2,000) coins sits on the ground; coin i from the top has integer value C_i (1 <= C_i <=…

面试题18.1:编写一个函数,将两个数字相加.不得使用+或其他算数运算符. package cc150.high; public class Add { public static void main(String[] args) { // TODO 自动生成的方法存根 } public int add(int a,int b){ //将两个数字相加,不得使用+或者其他算数运算符 if(b == 0) return a; int sum = a^b; //相加,但不进位 int carry =…