题目
以下为实现代码
1 判断一个字符
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
//用户输入一个字符，判断是数字、大写字母、小写字母还是其他字符
namespace 第三章作业
{
class Program
{
static void Main(string[] args)
{
string str;
label1:
Console.WriteLine("请输入一个字符：");
str=Console.ReadLine();
char key=(char)0;
//判断格式正确
if (str.Length > 1)
{
Console.WriteLine("你输入的太多了");
goto label1;
}
else if (str.Length == 0)
{
Console.WriteLine("你并没有输入");
goto label1;
}
else key = str[0];
//判断ascii
if(key>='0'&&key<='9')
{
Console.WriteLine("数字");
}
else if (key >= 'a' && key <= 'z')
{
Console.WriteLine("小写字母");
}
else if (key >= 'A' && key <= 'Z')
{
Console.WriteLine("大写字母");
}
else
{
Console.WriteLine("其他");
}
goto label1;
}
}
}
2 判断三角形
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace 三角形
{
class Program
{
static void Main(string[] args)
{
double a, b, c;
//输入
Console.WriteLine("请输入一条边长:");
a = double.Parse(Console.ReadLine());
Console.WriteLine("请输入一条边长:");
b = double.Parse(Console.ReadLine());
Console.WriteLine("请输入一条边长:");
c = double.Parse(Console.ReadLine());
//判断
if (a <= 0 || b <= 0 || c <= 0)
{
Console.WriteLine("边长不能为0或负数");
}
if (a + b > c && a + c > b && b + c > a)//两边之和大于第三遍
{
if (a == b || b == c || a == c)
{
Console.WriteLine("等腰三角形");
if (a * a + b * b - c * c <= 0.001 || b * b + c * c - a * a <= 0.001 || a * a + c * c - b * b <= 0.001)
{
Console.WriteLine("直角三角形");
}
}
else if (a * a + b * b == c * c || a * a == b * b + c * c || a * a + c * c == b * b)
{
Console.WriteLine("直角三角形");
}
else Console.WriteLine("普通三角形");
}
else Console.WriteLine("不是三角形");
}
}
}
3 千名学生
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace _3_千名学生
{
class Program
{
static void Main(string[] args)
{
int total;
Console.WriteLine("100~2000之间满足要求的数有：");
for (total = 100; total < 2000; total++)
{
if (total % 5 == 2 && total % 7 == 3 && total % 3 == 1)
{
Console.WriteLine(total);
}
}
}
}
}
4 a+aa+aaa+aaaa
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace _4_a_aa_aaa_aaaa
{
class Program
{
static void Main(string[] args)
{
int total = 0;
Console.WriteLine("a+aa+aaa+aaaa计算");
//输入重复次数
int n;
Console.WriteLine("请输入n");
n = int.Parse(Console.ReadLine());
//输入数字
int a;
Console.WriteLine("请输入a");
a = int.Parse(Console.ReadLine());
//相加
int i;
int j;
int curNum = 0;
Console.WriteLine("计算结果：");
for (i = 0; i < n; i++)//第i个数字
{
curNum = a;
for (j = 0; j < i; j++)
{
curNum *= 10;
curNum += a;
}
total += curNum;
Console.Write(curNum);
if (i != n - 1) Console.Write(" + ");
else if (i == n - 1) Console.Write(" = ");
}
Console.WriteLine(total);
}
}
}
5 求数列相加
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
//测试：n=6
//答案：0.383333333333333333333333
namespace _5_求数列相加
{
class Program
{
static void Main(string[] args)
{
//输入n
int n;
Console.WriteLine("请输入n");
n = int.Parse(Console.ReadLine());
//n+1项相加
int i;
double up;
double down;
int flag = 1;
double total = 0;
for (i = 0; i <= n; i++)
{
up = (i == 0 ? 1 : i); //分母
down = i + 1; //分子
total += (up / down) * flag; //总数
flag *= -1;
}
Console.WriteLine("total=" + total);
}
}
}
6 约瑟夫环
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace _6_10同学报数
{
class Program
{
static void Main(string[] args)
{
//输入总数
int total;
Console.WriteLine("请输入总人数：");
total = int.Parse(Console.ReadLine());
bool[] a = new bool[total];
//输入从第几个开始数
int begin;
Console.WriteLine("从第几个人开始：");
begin = int.Parse(Console.ReadLine());
//数到几
int count;
Console.WriteLine("从1数到几：");
count = int.Parse(Console.ReadLine());
//全部为true
for (int i = 0; i < total; i++)
{
a[i] = true;
}
//开始删除
int iter = begin - 1;
int countnum = 1;
int left = total;
while (left != 1) //如果剩一个人，停止
{
if (a[iter] == false)
{
iter++;
iter %= total;
continue;
}
if (countnum == 0) //如果当前人报3,删除这个人
{
a[iter] = false;
left--;
Console.Write(iter + 1 + " ");
}
iter++; //下一个人
iter %= total;
countnum++; //下一个人报的数
countnum %= count;
}
//剩下的数字
for (int i = 0; i < total; i++)
{
if (a[i] == true)
{
Console.Write("剩下的人是：" + (i + 1) + "\n");
break;
}
}
}
}
}
