update

Author: Light-City

practical_exercises/.README.md.un~

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+#include<iostream>
+using namespace std;
+int main(int argc, char const *argv[])
+{
+    int i,j,k,f;
+    for (i=1;i<=4;i++){
+        for (j=1;j<=30;j++)
+            cout<<" ";
+        for (k=1;k<=8-2*i;k++)
+            cout<<" ";
+        for (f=1;f<=2*i;f++)
+            cout<<'*';
+        cout<<endl;
+    }
+    for(i=1;i<=3;i++){
+        for (j=1;j<=30;j++)
+            cout<<" ";
+        for (f=1;f<=7-2*i;f++)
+            cout<<'*';
+        cout<<endl;
+    }
+    system("pause");
+    return 0;
+}

practical_exercises/10_day_practice/day1/打印练习.cpp

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+#include<iostream>
+using namespace std;
+int main(int argc, char const *argv[])
+{
+    int year;
+    bool isLeapYear;
+    cout<<"Enter the year: ";
+    cin>>year;
+    isLeapYear = (((year%4==0)&&(year%100!=0))||(year%400==0));
+    if(isLeapYear)
+    {
+        cout<<year<<" is a leap year"<<endl;
+    }
+    else
+    {
+        cout<<year<<" is not a leap year"<<endl;
+    }
+    system("pause");
+    return 0;
+}

practical_exercises/10_day_practice/day1/是否闰年‘.cpp

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+#include<iostream>
+
+
+一种条件编译指令注释
+
+
+//另一种注释方法
+#if 0
+asd
+#endif
+
+//打开注释
+//条件编译指令
+#if 1
+asData
+#endif

practical_exercises/10_day_practice/day1/注释.cpp

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+#include<iostream>
+using namespace std;
+//相同的内存地址
+union myun 
+{
+    struct { int x; int y; int z; }u; 
+    int k; 
+}a; 
+int main() 
+{ 
+    a.u.x =4;
+    a.u.y =5; 
+    a.u.z =6; 
+    a.k = 0; //覆盖掉第一个int空间值
+    printf("%d %d %d %d\n",a.u.x,a.u.y,a.u.z,a.k);
+    system("pause");
+    return 0;
+}

practical_exercises/10_day_practice/day1/联合体学习.cpp

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+# �ļ�����

practical_exercises/10_day_practice/day10/readme.md

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+//用cin输入字符串数据时，如果字符串中含有空白就不能完整输入。因为遇到空白字符时，cin就认为字符串结束了。
+#include<iostream>
+using namespace std;
+int main(int argc, char const *argv[])
+{
+    char a[50];
+    cout<<"please input a string:";
+    cin>>a;
+    cout<<a<<endl;
+    system("pause");
+    return 0;
+}
+/*
+若a的内容是：
+this is a string! 
+就难以输入啦！
+这样的数据应用输入流类的成员函数输入
+*/

practical_exercises/10_day_practice/day10/文件例题/12-1.cpp

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+#include<iostream>
+using namespace std;
+int main(int argc, char const *argv[])
+{
+    char stu[5][10];
+    int i;
+    for(i=0;i<5;i++)
+        cin.getline(stu[i],10,',');
+    for(i=0;i<5;i++)
+        cout<<stu[i]<<endl;
+    system("pause");
+    return 0;
+}

practical_exercises/10_day_practice/day10/文件例题/12-2应用.cpp

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+#include<iostream>
+using namespace std;
+//º¯ÊýÔ­ÐÍ
+//put(char c)
+//write(const char*c, int n)
+int main(){
+    char c;
+    char a[50]="this is a string...";
+    cout<<"use get() input char:";
+    while((c=cin.get())!='\n'){
+        cout.put(c);
+        cout.put('\n');
+        cout.put('t').put('h').put('i').put('s').put('\n');
+        cout.write(a,12).put('\n');
+        cout<<"look"<<"\t here!"<<endl;
+    }
+    system("pause");
+}

practical_exercises/10_day_practice/day10/文件例题/12-3.cpp

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+//Eg12-5.cpp
+#include<iostream>
+#include<iomanip>
+using namespace std;
+int main(){
+    char c[30]="this is string";
+    double d=-1234.8976;
+    cout<<setw(30)<<left<<setfill('*')<<c<<"----L1"<<endl;
+    cout<<setw(30)<<right<<setfill('*')<<c<<"----L2"<<endl;
+    //showbase显示数值的基数前缀
+    cout<<dec<<showbase<<showpoint<<setw(30)<<d<<"----L3"<<"\n";
+    //showpoint显示小数点
+    cout<<setw(30)<<showpoint<<setprecision(10)<<d<<"----L4"<<"\n";
+    //setbase(8)设置八进制
+    cout<<setw(30)<<setbase(16)<<100<<"----L5"<<"\n";
+    system("pause");
+}

practical_exercises/10_day_practice/day10/文件例题/12-5.cpp

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+//12-6.cpp
+#include<iostream>
+#include<fstream>
+using namespace std;
+int main(int argc, char const *argv[])
+{
+    fstream ioFile;
+    ioFile.open("./a.dat",ios::out);
+    ioFile<<"张三"<<"  "<<76<<" "<<98<<" "<<67<<endl;	//L3
+    ioFile<<"李四"<<"  "<<89<<" "<<70<<" "<<60<<endl;
+    ioFile<<"王十"<<"  "<<91<<" "<<88<<" "<<77<<endl;
+    ioFile<<"黄二"<<"  "<<62<<" "<<81<<" "<<75<<endl;
+    ioFile<<"刘六"<<"  "<<90<<" "<<78<<" "<<67<<endl;
+    ioFile.close();
+    ioFile.open("./a.dat",ios::in|ios::binary);
+    char name[10];
+    int chinese,math,computer;
+    cout<<"姓名\t"<<"英语\t"<<"数学\t"<<"计算机\t"<<"总分"<<endl; 
+    ioFile>>name;										
+    while(!ioFile.eof())	{								
+        ioFile>>chinese>>math>>computer;					
+        cout<<name<<"\t"<<chinese<<"\t"<<math<<"\t"<<computer<<"\t"<<chinese+math+computer<<endl;		
+        ioFile>>name;
+    }
+    ioFile.close();										
+    system("pause");
+    return 0;
+}

practical_exercises/10_day_practice/day10/文件例题/12-6.cpp

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+//Eg12-7.cpp
+#include <iostream>
+#include <fstream>
+using namespace std;
+int main(){
+    char ch;
+    ofstream out("/test.dat",ios::out|ios::binary);		//L1
+    for(int i=0;i<90;i++){
+        if(i>0 && (i % 30)==0)
+		    out.put('\n');						
+        out.put(i);							
+        out.put(' ');	
+        						
+	}
+    out.close();							    
+    ifstream in("/test.dat",ios::in|ios::binary);
+    while(in.get(ch))
+		cout<<ch;				
+	in.close();		
+    system("pause");					
+}

practical_exercises/10_day_practice/day10/文件例题/12-7.cpp

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+//Eg12-12.cpp
+#include <iostream>
+#include <cstring>
+#include <fstream>
+using namespace std;
+class Employee{
+private:
+    int number ,age;
+    char name[20];
+    double sal;
+public:
+    Employee(){}
+    Employee(int num,char* Name,int Age, double Salary){
+        number=num;
+        strcpy(name,Name);
+        age=Age;
+        sal=Salary;
+    }
+    void display(){
+        cout<<number<<"\t"<<name<<"\t"<<age<<"\t"<<sal<<endl;
+    }
+};
+
+int main(){
+    ofstream out("D:/Employee.dat",ios::out);	//定义随机输出文件
+    Employee e1(1,"张三",23,2320);
+    Employee e2(2,"李四",32,3210);
+    Employee e3(3,"王五",34,2220);
+    Employee e4(4,"刘六",27,1220);
+    out.write((char*)&e1,sizeof(e1));		//按e1,e2,e3,e4顺序写入文件
+    out.write((char*)&e2,sizeof(e2));
+    out.write((char*)&e3,sizeof(e3));
+    out.write((char*)&e4,sizeof(e4));
+
+     //下面的代码将e3（即王五）的年龄改为40岁   
+    Employee e5(3,"王五",40,2220);
+    out.seekp(3*sizeof(e1));		//指针定位到第3（起始为0）个数据块
+    out.write((char*)&e5,sizeof(e5));	//将e5写到第3个数据块位置，覆盖e3
+    out.close();			//关闭文件
+    system("pause");
+}

practical_exercises/10_day_practice/day10/文件例题/12-9.cpp

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+//【例12-2】  用函数get和getline读取数据。
+#include <iostream>
+using namespace std;
+int main()
+{
+	char a,b,c,d;
+	cin.get(a);
+	cin.get(b);
+	c = cin.get();
+	d = cin.get();
+	cout<<int(a)<<','<<int(b)<<','<<int(c)<<','<<int(d)<<endl;
+    system("pause");
+    return 0;
+}
+
+/*
+用法：a = cin.get() ?或者 ?cin.get(a)
+结束条件：输入字符足够后回车
+说明：这个是单字符的输入，用途是输入一个字符，把它的ASCALL码存入到a中
+处理方法：与cin不同，cin.get()在缓冲区遇到[enter]，[space]，[tab]不会作为舍弃，而是继续留在缓冲区中
+*/

practical_exercises/10_day_practice/day10/文件例题/三种输入格式/get()12-2.cpp

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+
+//【例12-2】  用函数get和getline读取数据。
+#include <iostream>
+using namespace std;
+//cin.get(arrayname,size)  把字符输入到arrayname中，长度不超过size
+int main()
+{
+    //get()两个参数
+
+    //1.输入串长<size，输入串长>arraylength，会自动扩张arrayname大小，使能保存所有数据
+	// char a[10];
+	// cin.get(a,20);
+	// cout<<a<<endl;
+    // cout<<sizeof(a)<<endl;
+    //2.输入串长<size，输入串长<arraylength，把串全部输入，后面补‘\0’
+    // char b[10];
+	// cin.get(b,20);
+	// cout<<b<<endl;//12345，此时数组内数据为‘12345'\0’
+    // cout<<sizeof(b)<<endl;
+    //3.输入串长>size，先截取size个字符，若还是大于arraylength，则输入前arraylength-1个字符，最后补充‘\0’
+    // char c[5];
+	// cin.get(c,10);
+	// cout<<c<<endl;
+    // cout<<sizeof(c)<<endl;
+    //4.输入串长>size，先截取size个字符，若小于arraylength，则把截取串放入数组中，最后补充‘\0’
+    // char d[10];
+	// cin.get(d,5);
+	// cout<<d<<endl;
+    // cout<<sizeof(d)<<endl;
+    
+    //get()三个参数
+    /*
+        用法：cin.get(arrayname,size,s) ?把数据输入到arrayname字符数组中，当到达长度size时结束或者遇到字符s时结束
+        注释：a必须是字符数组，即char a[]l类型，不可为string类型；size为最大的输入长度；s为控制，遇到s则当前输入结束缓存区里的s将被舍弃
+
+    */
+    int i;
+    char e[10];
+    cin.get(e,8,',');
+    cout<<e;
+    system("pause");
+    return 0;
+}
+

practical_exercises/10_day_practice/day10/文件例题/三种输入格式/get(a,size)12-2-1.cpp

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+#include<iostream>
+using namespace std;
+/*
+（1）cin.getline(arrayname,size)与cin.get(arrayname,size)的区别
+cin.get(arrayname,size)当遇到[enter]时会结束目前输入，他不会删除缓冲区中的[enter]
+cin.getline(arrayname,size)当遇到[enter]时会结束当前输入，但是会删除缓冲区中的[enter]
+*/
+int main()
+{
+    /*
+	char a[10];
+    char b;
+    cin.get(a,10);
+	cin.get(b);
+    cout<<a<<endl<<int(b);//输入：12345[enter] 输出：12345 【换行】 10*/
+    /*char c[10];
+    char d;
+    cin.getline(c,10);
+    cin.get(d);
+	cout<<c<<endl<<int(d);//输入：12345[enter]a[enter] 输出：12345【换行】97*/
+    //cin.getline(arrayname,size,s)与cin.gei(arrayname,size,s)的区别
+    /*
+    cin.getline(arrayname,size,s)当遇到s时会结束输入，并把s从缓冲区中删除
+    cin.get（arrayname,size,s）当遇到s时会结束输入，但不会删除缓冲区中的s
+    */
+   /*
+    char e[10];
+    char f;
+    cin.get(e,10,',');
+	cin.get(f);
+	cout<<e<<endl<<f;//输入：12345,[enter] 输出：12345【换行】，说明：cin,get不会删除缓冲区的，*/
+    char e1[10];
+    char f1;
+    cin.getline(e1,10,',');
+	cin.get(f1);
+	cout<<e1<<endl<<f1;//输入：asd,wqe 输出：asd【换行】w
+    system("pause");
+}

practical_exercises/10_day_practice/day10/文件例题/三种输入格式/getline()12-2-2.cpp

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+#include<iostream>
+using namespace std;
+
+int main(int argc, char const *argv[])
+{
+    char c[30]="this is string";
+    double d = -1231.232;
+    cout.width(30);
+    cout.fill('*');
+    cout.setf(ios::left);
+    cout<<c<<"----L1"<<endl;
+    cout.width(30);
+    cout.fill('-');
+    cout.setf(ios::right);
+    cout<<c<<"----L2"<<endl;
+    cout.setf(ios::dec|ios::showbase|ios::showpoint);
+    cout.width(30);
+    cout<<d<<"----L3"<<"\n";
+    cout.setf(ios::showpoint);
+    cout.precision(10);
+    cout.width(30);
+    cout<<d<<"----L4"<<"\n";
+    cout.width(30);
+    cout.setf(ios::oct,ios::basefield);
+    cout<<100<<"----L5"<<"\n";
+    system("pause");
+    return 0;
+}