console.writeline("he")
static int J(int n)
{
if (n==0)
{
return 1;
}
int res = J(n - 1) * n;
return res;
}
static void test05()
{
int res = 1;
for (int i = 1; i < 11; i++)
{
res = res * i;
}
Console.WriteLine(res);
}
static int J(int n)
{
if (n==0)
{
return 1;
}
int res = J(n - 1) * n;
return res;
}
static void test05()
{
int res = 1;
for (int i = 1; i < 11; i++)
{
res = res * i;
}
Console.WriteLine(res);
}
static void Main(string[] args)
{
//test01();
//test02();
//test03();
//test04();
//int res=F(40);
//Console.WriteLine("res="+res);
int res1 = J(10);
Console.WriteLine("res1=" + res1);
test05();
}
static void test04()
{
//int num = Convert.ToInt32(Console.ReadLine());
int f0 = 2;
int f1 = 3;
int n = 0;
for (int i = 2; i < 41; i++)
{
n = f0 + f1;
f0 = f1;
f1 = n;
}
Console.WriteLine(n);
}
static int F(int n)
{
if (n==0)
{
return 2;
}
if (n==1)
{
return 3;
}
int res = F(n - 1) + F(n - 2);
return res;
}
static bool IsSu(int number)
{
bool isSu = true;
for (int j = 2; j < number-1; j++)
{
if (number% j == 0)
{
isSu = false;
break;
}
}
return isSu;
}
static int opposite(int number)//反序
{
int temp = number;
int num = 0;
while (temp % 10 != 0)//反序
{
num = num * 10 + temp % 10;
temp = temp / 10;
}
return num;
}
static void test01()
{
string str = Console.ReadLine();
string[] strArray = str.Split(' ');
int[] intArray = new int[strArray.Length];
for (int j = 0; j < strArray.Length; j++)
{
int number = Convert.ToInt32(strArray[j]);
intArray[j] = number;
}
int m = intArray[0];
int n = intArray[1];
for (int i = m; i <= n; i++)
{
bool isSu =IsSu(i);
//for (int j = 2; j < i; j++)
//{
// if (i % j == 0)
// {
// issu = false;
// break;
// }
//}
if (isSu)
{
//int temp = i;
//int num = 0;
//while (temp % 10 != 0)//反序
//{
// num = num * 10 + temp % 10;
// temp = temp / 10;
//}
int temp = i;
int num = opposite(temp);
bool isSuFan = IsSu(num);
//for (int j = 2; j < num; j++)
//{
// if (num % j == 0)
// {
// isSuFan = false;
// break;
// }
//}
if (isSuFan == true)
{
Console.Write(i + " ");
}
}
}
}
static void test06()
{
string str = Console.ReadLine();
int[] countArray = new int[26];
for (int i = 0; i < str.Length; i++)
{
countArray[str[i] - 'a'] = countArray[str[i] - 'a'] + 1;
}
for (int i = 0; i < countArray.Length; i++)
{
Console.Write(countArray[i]+" ");
}
bool isFind = false;
char c = ' ';
for (int i = 0; i < str.Length; i++)
{
if (countArray[str[i] - 'a'] == 1)
{
isFind = true;
c = str[i];
break;
}
}
Console.WriteLine();
if (isFind==false)
{
Console.WriteLine("no");
}
else
{
Console.WriteLine(c);
}
}
\\代表一个斜杠，即第一个\把后面那个转译了
打印“\"”, （"\\\""）,\为转译符号
打印siki说：“what is \n”, （"siki说：\"what is \\n\""）
static void test01()
{
string str = Console.ReadLine();
bool isRight = true;
for (int i = 0; i < str.Length; i++)
{
if ((str[i] < '0' || str[i] > '9')&& (str[i] < 'a' || str[i] > 'z')
&& (str[i] < 'A' || str[i] > 'Z')&& (str[i] !='_' ))//不是小写字母，不是大写字母，不是下划线,不是数字
{
isRight = false;
break;
}
}
if (str[0] >='0'|| str[0]<='9')
{
isRight = false;
}
if (isRight)
{
Console.WriteLine("是合法标识符");
}
else
{
Console.WriteLine("不是合法标识符");
}
}
static void test12()
{
Console.WriteLine("请输入一个数组：");
string str = Console.ReadLine();
string[] strArray = str.Split(' ');
int[] intArray = new int[strArray.Length];
bool isChange = false;
for (int i = 0; i < strArray.Length; i++)
{
Console.Write(strArray[i] + " ");
int num = Convert.ToInt32(strArray[i]);
intArray[i] = num;
}
for (int j = 0; j < intArray.Length-1; j++)//length-1轮比较
{
for (int i = 0; i < intArray.Length-1; i++)
{
if (intArray[i]>intArray[i+1])
{
int temp = intArray[i];
intArray[i] = intArray[i + 1];
intArray[i + 1] = temp;
isChange = true;
}
}
if (isChange==false)
{
break;
}
}
Console.WriteLine();
foreach (int temp in intArray)
{
Console.Write(temp+" ");
}
}
Console.ReadLine( )
类型一致，
Convert.ToiInt32
static void test10()
{
Console.WriteLine("请输入一个有序的数组：");
string str = Console.ReadLine();
string[] strArray = str.Split(' ');
int[] intArray = new int[strArray.Length];
for (int i = 0; i < strArray.Length; i++)
{
int num = Convert.ToInt32(strArray[i]);
intArray[i] = num;
}
Console.WriteLine("请输入一个整数：");
int n = Convert.ToInt32(Console.ReadLine());
int m = intArray.Length-1;
//bool find = false;//默认是未找到索引位置 m<=x<=x+1
for (int i = 0; i < intArray.Length-1; i++)
{
if (n>=intArray[i]&&n<=intArray[i+1])
{
m = i;
//find = true;
break;
}
}
if (n<intArray[0])
{
m = -1;
}
int[] intArray1 = new int[intArray.Length + 1];
for (int i = 0; i < m+1; i++)
{
intArray1[i] = intArray[i];
}
intArray1[m + 1] = n;
for (int i = m+1; i < intArray.Length; i++)
{
intArray1[i+1] = intArray[i];
}
foreach (int temp in intArray1)
{
Console.Write(temp+" ");
}
//if (find==false)
//{
// m = intArray.Length - 1;
//}
}
static void test05()
{
int[] arr = new int[9] { 1, 2, 3, 4, 5, 6, 7, 8, 9 };
char[] arr1 = new char[20] { 'a','b', 'b', 'b', 'b', 'b', 'b', 'b', 'b', 'b', 'b', 'b', 'b', 'b', 'b', 'b', 'b', 'b', 'b', 'b' };
float[] arr2 = new float[5] { 1.2f, 2.5f, 2.3f, 2.4f, 5.3f};
string[] arr3 = new string[8] { "a", "b", "c", "d", "e", "f", "g", "h", };
int[] arr4 = new int[9];
char[] arr5 = new char[20];
float[] arr6 = new float[5];
string[] arr7 = new string[8];
for (int i = 0; i < 5; i++)
{
Console.WriteLine(arr6[i]);
}
for (int i = 8; i >=0; i--)
{
Console.WriteLine(arr[i]);
}
foreach (int temp in arr1)
{
Console.WriteLine(temp);
}
Console.WriteLine(arr.Length);
}
static void test06()
{
string name = "missuu";
for (int i = 0; i < name.Length; i++)
{
Console.Write(" " + name[i]);
}
Console.WriteLine();
for (int i = name.Length-1; i >=0; i--)
{
Console.Write(" "+name[i]);
}
Console.WriteLine();
Console.WriteLine(name.ToLower());//小写
Console.WriteLine(name.ToUpper());//大写
name = " missuu ";
Console.WriteLine(name.TrimStart() + "|");
Console.WriteLine(name.TrimEnd() + "|");
}
static void test01()
{
for (int a = 1; a <=33; a++)
{
for (int b = 1; b <= 20; b++)
{
for (int c = 0; c <= 50; c++)
{
if (3*a+5*b+c*2==100)
{
Console.WriteLine("a={0},b={1},c={2}",a,b,c);
}
}
}
}
}
变量：不同物品不同容器盛放
浮点数：带小数的数字（包括整数，例如1.0）
结构体
struct 结构体名{
public 类型 变量名1；
⬆访问权限 类型 变量名2；
}
结构名 变量名；
变量名.变量名1=xxx；
变量名.变量名2=xxx；
枚举
定义
enum aaaa
{
值1，值2，值3
}
aaaa 变量名=aaaa.值x；
int name;
double jishuqi;
double pjs;
int shengao;
int zonhe;
double wendu;
using System;
namespace _0026_编程题__0_3_
{
internal class Program
{
private static void Main(string[] args)
{
//让⽤户输⼊两个整数，然后再输⼊0-3之间的⼀个数，0代表加法，1代表减法，2代表乘法，
//0代表加法，1代表减法，2代表乘法，3代表除法,计算这两个数字的结果.
Console.WriteLine("输入俩个数");
int a = Convert.ToInt32(Console.ReadLine());
int b = Convert.ToInt32(Console.ReadLine());
Console.WriteLine("输入0-3之间的⼀个数，0代表加法，1代表减法，2代表乘法");
int c = Convert.ToInt32(Console.ReadLine());
switch (c)
{
case 0:
Console.WriteLine(a + "加" + b + "等于" + (a + b));
break;
case 1:
Console.WriteLine(a + "减" + b + "等于" + (a - b));
break;
case 2:
Console.WriteLine(a + "乘" + b + "等于" + (a * b));
break;
}
}
}
}
输入语句：
- Console.ReadLine(); 等待控制台输入(字符串)
输出语句：
- Console.WriteLine(); 在控制台输出
数据类型转换：
- Convert.ToInt32()；
int a = Convert.ToInt32(Console.ReadLine());
C#取消转义字符：
- 字符串前加@“”
字符串类型：
- string 字符串类型
字符串取消转义后输出引号时需要用2个引号表示
数据类型：
int 整型
double 浮点型
char 字符型
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