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：
输出语句：
数据类型转换：
int a = Convert.ToInt32(Console.ReadLine());
C#取消转义字符：
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
delegate
static void test09()
{
for (int i = 100; i < 1000; i++)
{
//Console.WriteLine(i);
int a = i / 100;
int b = (i / 10) % 10;
int c = i % 10;
if (i==a*a*a+b*b*b+c*c*c)
{
Console.WriteLine(i);
}
}
}
static void test10()
{
Console.WriteLine("请输入一个整数n：");
int n = Convert.ToInt32(Console.ReadLine());
while (n!=0)
{
int a = n % 10;
Console.WriteLine("a="+a);
n /= 10;
}
}
static void test11()
{
Console.WriteLine("请输入一个整数n：");
int n = Convert.ToInt32(Console.ReadLine());
int sum = 0;
int b = 1;
while (n != 0)
{
int a = n % 10;
if (a!=0)
{
a *= b;
sum += a;
b *= 10;
Console.WriteLine(sum);
}
n /= 10;
}
Console.WriteLine(sum);
}
multiply
注释快捷键：
转义字符：
注意：每行必须以“；”结束
sqrt
static void test03()
{
Console.WriteLine("请输入一个整数a：");
int a = Convert.ToInt32(Console.ReadLine());
Console.WriteLine("请输入一个正整数n：");
int n = Convert.ToInt32(Console.ReadLine());
int res = 1;
for (int i = 0; i < n; i++)
{
res *= a;
}
Console.WriteLine("{0}的{1}次方是:{2}",a,n,res);
}
static void test04()
{
Console.WriteLine("请输入一个整数n：");
int n = Convert.ToInt32(Console.ReadLine());
int res = 1;
for (int i = 1; i <= n; i++)
{
res *= i;
Console.WriteLine("res="+res);
}
}
static void test05()
{
Console.WriteLine("请输入一个整数n：");
int n = Convert.ToInt32(Console.ReadLine());
Console.WriteLine("请输入一个整数q：");
int q = Convert.ToInt32(Console.ReadLine());
int temp = 1;
int res = 0;
for (int i = 1; i <= n; i++)
{
temp *= q;
res += temp;
Console.WriteLine("temp=" + temp);
Console.WriteLine("res=" + res);
}
res++;
Console.WriteLine("res=" + res);
}
知道执行次数 清楚首尾 for循环
终止条件充足 while
static void test06()
{
for (int i = 0; i < 20; i++)
{
Console.Write("* ");
}
}
static void test07()
{
int sum = 0;
for (int i = 1; i < 101; i++)
{
sum += i;
Console.WriteLine(sum);
}
Console.WriteLine(sum);
}
static void test08()
{
for (int i = 1 ; i < 101; i++)
{
if (i%2==0)
{
Console.WriteLine(i);
}
}
}
static void test09()
{
Console.WriteLine("请输入整数n：");
int n = Convert.ToInt32(Console.ReadLine());
Console.WriteLine("请输入整数m：");
int m = Convert.ToInt32(Console.ReadLine());
int sum1 = 0;
int sum2 = 0;
if (m > n)
{
for (int i = n; i <= m; i++)
{
if (i % 7 == 0)
{
Console.WriteLine(i);
sum1 += i;
}
}
Console.WriteLine("所有能被7整除的数的和是：" + sum1);
}
else if (m < n)
{
for (int i = m; i <= n; i++)
{
if (i % 7 == 0)
{
Console.WriteLine(i);
sum2 += i;
}
}
Console.WriteLine("所有能被7整除的数的和是：" + sum2);
}
else
{
if (m%7==0)
{
Console.WriteLine(m);
Console.WriteLine("所有能被7整除的数的和是：" + m);
}
}
}
static void test10()
{
Console.WriteLine("请输入整数n：");
int n = Convert.ToInt32(Console.ReadLine());
Console.WriteLine("请输入整数m：");
int m = Convert.ToInt32(Console.ReadLine());
string odd="";
string even="";
if (m > n)
{
for (int i = n; i <= m; i++)
{
if (i % 2 == 0)
{
odd += i+" ";
}
else
{
even += i+" ";
}
}
Console.WriteLine(odd);
Console.WriteLine(even);
}
else if (m < n)
{
for (int i = m; i <= n; i++)
{
if (i % 2 == 0)
{
odd += i + " ";
}
else
{
even += i + " ";
}
}
Console.WriteLine(odd);
Console.WriteLine(even);
}
else
{
if (m % 2 == 0)
{
Console.WriteLine(m);
}
else
{
Console.WriteLine(m);
}
}
}
static void test02()
{
int student = 80000;
int year = 2006;
while (student<200000)
{
student =(int )(student* 1.25);
year++;
Console.WriteLine("student="+student);
}
Console.WriteLine("year="+year);
}
static void test03()
{
Console.WriteLine("请输入学生个数：");
int student = Convert.ToInt32(Console.ReadLine());
double sum = 0;
for (int i = 1; i <= student; i++)
{
Console.WriteLine("请输入{0}号学生的年龄：", i);
double old = Convert.ToInt32(Console.ReadLine());
sum += old;
}
double averageValue=sum/student;
Console.WriteLine("平均年龄是：{0}",averageValue);
}
static void test04()
{
Console.WriteLine("请输入整数n：");
int n = Convert.ToInt32(Console.ReadLine());
for (int i = 1; i <=n; i++)
{
Console.Write(" "+i);
}
}
static void test01()
{
Console.WriteLine("请输入整数n：");
int n = Convert.ToInt32(Console.ReadLine());
for (int i = 0; i >=0; i++)
{
if (n>1)
{
break;
}
else
{
Console.WriteLine("输入有误，请重新输入：");
n = Convert.ToInt32(Console.ReadLine());
}
}
int j = 0;
while (n>1)
{
if (n % 2 != 0)
{
n = 3 * n + 1;
}
else if (n % 2 == 0)
{
n /= 2;
}
j++;
Console.WriteLine("每次变换后n=" + n);
}
Console.WriteLine("变换次数j是：" + j);
}
static void test11()
{
Console.WriteLine("请输入整数n1：");
int n1 = Convert.ToInt32(Console.ReadLine());
Console.WriteLine("请输入整数n2：");
int n2 = Convert.ToInt32(Console.ReadLine());
Console.WriteLine("你输入的n1是：{0},你输入的n2是：{1}",n1,n2);
int i = n1;
if (n2>n1)
{
while (i<=n2)
{
if (i%2==0)
{
Console.WriteLine(i);
}
i++;
}
}
else
{
while (i >= n2 )
{
if (i % 2 == 0)
{
Console.WriteLine(i);
}
i--;
}
}
}
