int x;
x = 924;

a = a*a*a; //或
for (int i=0; i<3; i++) a=a*a;

if (date == "0924") {
    cout << "First class!\n";
}

string str;
str = "Hello";
cout << str + "World!\n";

x = 924;

a = a**3;

if date == "0924":
    print("First class!")

str = "Hello"
print(str + " world!")

#include<iostream>
using namespace std;

int main () {
  cout << "Hello world";
  return 0;
}

#include<iostream> //引入C++, 輸出輸入的函式庫 (input output stream)
using namespace std; //讓你少打一些code的東西

int main () { //主函式
  
  return 0; //可加可不加, 加一下比較好, 之後在教函數時就會瞭啦
} //大括號!!

#include<iostream>
using namespace std;

int main () {
  cout << "Hello world"; //加這行
  return 0;
}

  std::cout << "Hello world";

#include<bits/stdc++.h>
using namespace std;

int main () {
  string name;
  cin >> name;
  cout << "Hello, " << name << "!";
  return 0;
}

  std::cin >> name;

#include<iostream>
#include<string>
using namespace std;

int main() {
	string str;
	cin >> str;
	cout << "hello, " << str;
	return 0;
}

a^2+2*a*b+b^2=(a+b)^2
x+y=4, x-y=2  x=3, y=2
y=f(x)=ax+b
a^2+b^2=c^2
...

int a = -2147483648;
char _b = 'b';
long long int c = 9223372036854775807;
float d = 3.1415926; //7位
double e = 3.141592653589793; //15位
...

int num_1, num_2, num_3; 
//宣告整數型, 分別叫num_1, num_2, num_3的變數
int num_4 = 3; 
//宣告一個整數型, 叫num_4的變數, 並分配一個整數給它(賦值)
num_1 = 1; //賦值
cin>> num_2; 
//輸入一個整數進num_2
num_3 = num_1 + num_2
cout<< num_1<<" "<< num_2<< " "<< num_3<< " "<<num_4; 
//分別輸出值

Q: 要輸入己才能輸出"1 1 2 3"的費式數列??

















A: 1

int var;  //宣告一個名為var的整數
cin >> var;  //把值輸進var
cout << var;  //輸出var

char c = 'C';  //宣告名為c的字元，並賦值'C'
cout << c << " " << c;  //輸出C C

double a, b = 10.08;  
//宣告名為a、b的，並於b賦值10.08
a = b;  //於a賦值b的值，也就是 a=10.08
cout << a << b;  //輸出10.0810.08

bool _b = false;  //宣告名為_b的布林值，並賦值false
_b = true;  //將_b改為true
cout << "bool" << _b;  //輸出bool1

#include<iostream>
using namespace std;

int main() {
	string str;
	cin >> str;
	cout << "hello, " << str;
	return 0;
}

#include<iostream>
using namespace std;

int main() {
    int a, b;
    cout << a+b;
    return 0;
}

#include<iostream>
using namespace std;

int main() {
    int a, b;
    int ans;
    ans = a + b;
    cout << ans;
    return 0;
}

#include<iostream>
using namespace std;

int main() {
    int M, D;
    cin >> M >> D;
    if ((M*2+D)%3 == 0) cout << "普通";
    else if ((M*2+D)%3 == 1) cout << "吉";
    else cout << "大吉";
    return 0;
}

if(要判斷的條件){
    //條件成立時要執行的指令
}

if(score>=60){
    cout<<"PASS";
}

if(score>=60){
    cout<<"PASS";
    credits+=1;
}

#include <iostreram>
using namespace std;
int main(){
    int score,credits=0;
    cin>>score;
    if(score>=60){
        cout<<"PASS";
        credits+=1;
    }
    return 0;
}

if(7>5&&3<=4){
    cout<<"YES";
}

if(1<0||5==5){
    cout<<"YES";
}

if(要判斷的條件){
    //條件成立時要執行的指令
}
else{
    //條件不成立時要執行的指令
}

if(score>=60){
    cout<<"PASS";
}
else{
    cout<<"FAIL";
}

#include <iostreram>
using namespace std;
int main(){
    int score;
    cin>>score;
    if(score>=60){
        cout<<"PASS";
    }
    else{
        cout<<"FAIL";
    }
    return 0;
}

if(條件1){
    //條件1成立時要執行的指令
}
else if(條件2){
    //不滿足條件1但條件2成立時要執行的指令
}
else{
    //以上條件皆不成立時要執行的指令
}

if(score>=80){
    cout<<"excellent";
}
else if(score>=60){
    cout<<"good";
}
else{
    cout<<"keep going";
}

#include <iostream>
using namespace std;
int main(){
    int score;
    cin>>score;
    if(score>=80){
        cout<<"excellent";
    }
    else if(score>=60){
        cout<<"good";
    }
    else{
        cout<<"keep going";
    }
    return 0;
}

if(條件1){
    //條件1成立時要執行的指令
}
else if(條件2){
    //條件2成立時要執行的指令
}
else if(條件3){
    //條件3成立時要執行的指令
}
             .  .  .
else{
    //以上條件皆不成立時要執行的指令
}

#include <iostream>    
using namespace std;    
int main(){    
    int score=95;    
    if(score<60){    
        cout<<"E";    
    }    
    else if(score>=60){    
        cout<<"D";    
    }    
    else if(score>=70){
        cout<<"C";    
    }    
    else if(score>=80){
        cout<<"B";    
    }    
    else{
        cout<<"A";    
    }    
    return 0;    
} 

#include <iostream>    
using namespace std;    
int main(){    
    int score=95;    
    if(score>=90){    
        cout<<"A";    
    }    
    else if(score>=80){    
        cout<<"B";    
    }    
    else if(score>=70){
        cout<<"C";    
    }    
    else if(score>=60){
        cout<<"D";    
    }    
    else{
        cout<<"E";    
    }    
    return 0;    
} 

#include <iostream>    
using namespace std;    
int main(){    
    int score=95;    
    if(score>=90){    
        cout<<"A";    
    }    
    if(score>=80){    
        cout<<"B";    
    }    
    if(score>=70){
        cout<<"C";    
    }    
    if(score>=60){
        cout<<"D";    
    }    
    if(score<60){
        cout<<"E";    
    }    
    return 0;    
} 

switch(變數名稱){
    case 條件1:
        //條件1成立時執行的指令
        break;
    case 條件2:
        //條件2成立時執行的指令
        break;
        . . . 
    default:
        //以上皆不成立時執行的指令
}
//條件只能為某個整數或字元，或者是整數或字元的區間

int score;
cin>>score;
switch(score){
    case 100:       //意思為score==100
        cout<<"滿分";
        break;
    case 60 ... 99: //包含60及99
        cout<<"及格";
        break;
    default:
        cout<<"不及格";
}

char grade;
cin>>grade;
switch(grade){
    case 'A':
        cout<<"90~100";
        break;
    case 'B':
        cout<<"80~89";
        break;
    case 'C':
        cout<<"70~79";
        break;
    case 'D':
        cout<<"60~69";
        break;
    case 'E':
        cout<<"0~59";
        break;
    case 'F' ... 'Z':
        cout<<"error";
        break;
}

#include <iostream>
using namespace std;

int main () {
    cout << "again and ";
    cout << "again and ";
    cout << "again and ";
    ...
    cout << "again and ";
    cout << "again";
    return 0;
}

#include <iostream>
using namespace std;

int main () {
    int n;
    cin >> n;
    while (n--) {
        cout << "again and ";
    }
    cout << "again";
    return 0;
}

while(condition){ //條件
    statement; //內容
    //do something...
}

#include<iostream>
using namespace std;

int main(){
    int i = 1;
    while(i <= 99){
    	cout << i <<endl;
        i++;
    }
    return 0;
}

#include<iostream>
using namespace std;

int main(){
    int i = 99;
    while(i >= 1){
    	cout << i <<endl;
        i--;
    }
    return 0;
}

#include<iostream>
using namespace std;

int main(){
    int i = 99;
    while(i){  //當 i 為 true   // i != 0
    	cout << i <<endl;
        i--;
    }
    return 0;
}

for((宣告)初始化變數; 條件; 更新){
    statement;  //內容
    //do something...
}

#include<iostream>
using namespace std;

int main(){
    for(int i = 1; i <= 99; i++){
    	cout << i <<endl;
    }
    return 0;
}

#include<iostream>
using namespace std;

int main(){
    for(int i = 99; i >= 1; i--){
    	cout << i <<endl;
    }
    return 0;
}

for(int i=0; i<5; i++){ //外層迴圈
    for(int j=0; j<5; j++){ //內層迴圈
    	cin>> array[i][j];
    }
}

#include<iostream>
using namespace std;

int main(){
    int i = 1, j = 1;
    while(i <= 10){
    	while(j <= 10){
    		cout << i << "*" << j;
            cout<< "=" << i*j << " " ;
    		j++;
        }
        cout << endl;
        j = 1;
        i++;
    }
    return 0;
}

while(1){ 
    //do something...
}

#include<iostream>
using namespace std;

int main(){
  while(1) cout << "true ";
  return 0;
}

for(int i=0; i<5; i++){ 
    if(i==3) break;
    cout<< i<<" ";
}
//0 1 2

for(int i=0; i<5; i++){ 
    if(i==3) continue;
    cout<< i<<" ";
}
//0 1 2 4

#include <iostream>
using namespace std;

int main(){
    int n;
    while(cin >> n){
        if(n <= 0)
            break;
        else if(n >= 99999)
            continue;
        else if(n % 2 == 1)
            cout << "odd" << endl;
        else
            cout << "even" << endl;
    }
    return 0;
}

#include<iostream>
using namesapce std;
int a=5;
int main(){
    int x=1;
    for(int i=0; i<3; i++){
        cout<< i<< " "; //ok
        cout<< x<< " "; //ok
        cout<< a<< " "; //ok
    }
    cout<< i; //X
    return 0;
}

while(condition){ //條件
    statement; //內容
    //do something...
}

for((宣告)初始化變數; 條件; 更新){
    statement;  //內容
    //do something...
}

for(int i=0; i<5; i++){ //外層迴圈
    for(int j=0; j<5; j++){ //內層迴圈
    	cout<< i << j <<endl;
    }
}

int s1,s2,s3,s4,s5,s6,s7,s8,s9,s10;

int s1
int s2
.........
int s100

int a[7];
for(int i=0;i<7;i++) a[i]=i;

int a[10];
cout<<a[100]<<endl;
cout<<a[1000]<<endl;

int n;
int a[n];

int s[100];
for(int i=0;i<100;i++){
    cin>>s[i];
}

int chinese[10],math[10];

int chinese[10],math[10],english[10],social[10],science[10];

int a[2][5];
double b[7][1][2];

int a[3][3];
for(int i=0;i<3;i++){
    for(int j=0;j<3;j++) 
    	a[i][j]=i+j;
}

for(int i=0;i<n;i++){
    for(int j=0;j<m;j++)
    {
        cin>>a[i][j];
    }
}//輸入陣列
for(int i=0;i<a;i++){
    for(int j=0;j<b;j++)
    {
        cout<<a[c][d]<<" ";
    }
    cout<<endl;
}//翻轉陣列

cout<<""\o_o/""<<endl;

#include<iostream>
using namespace std;
int main(){
  cout<<"                            _\n";
  cout<<"                          .\' `\'.__\n";
  cout<<"                         /      \\ `\'\"-,\n";
  cout<<"        .-\'\'\'\'--...__..-/ .     |      \\\n";
  cout<<"      .\'               ; :\'     \'.      |\n";
  cout<<"     /                 | :.       \\   o  \\\n";
  cout<<"    ;                   \\\':.      /  ,-.__;.-;`\n";
  cout<<"   /|     .              \'--._   /-.7`._..-;`\n";
  cout<<"  ; |       \'                |`-\'      \\  =|\n";
  cout<<"  |/\\        .   -\' /     /  ;         |  =/\n";
  cout<<"  (( ;.       ,_  .:|     | /     /\\   | =|\n";
  cout<<"   ) / `\\     | `\"\"`;     / |    | /   / =/\n";
  cout<<"     | ::|    |      \\    \\ \\    \\ `--\' =/\n";
  cout<<"    /  \'/\\    /       )    |/     `-...-`\n";
  cout<<"   /    | |  `\\    /-\'    /;\n";
  cout<<"   \  ,,/ |    \\   D    .\'  \\\n";
  cout<<"    `\"\"`   \\  nnh  D_.-\'L__nnh\n";
  cout<<"            `\"\"\"`\n";
  return 0;
} 
	

char a='s';
cout<<a;  //s
char b[7]="ZSISC";

char a=65;
char b=48;
cout<<a;
//A
cout<<b;
//0
cout<<a+b;
//113
a=a+2;
cout<<a;
//C
char c[10]="ZSISC27";
cout<<c+2;
//ISC27;

string a="ZSISC";
cout<<a;  //ZSISC
cout<<a[2]; //I

#include<iostream>

int func(int a, int b) {
	return a+b; 
}

int main() {
    std::cout << func(2, 3);
    return 0;
}

TYPE FUNCTION(TYPE PARAMETER1, TYPE PARAMETER2, ..) {
    //do something...
    
    return SOMETHING;
}

TYPE FUNCTION(TYPE PARAMETER1, TYPE PARAMETER2, ..) {
    //do something...
    
    return SOMETHING;
}

int func(int a, int b) {
    int c = a+b;
    return c; 
}

TYPE FUNCTION(TYPE PARAMETER1, TYPE PARAMETER2, ..) {
    //do something...
    
    return SOMETHING;
}

void func() {
    cout << "HelloHa";
}

int main() {
    TYPE result = FUNCTION(PARAMETER);
    return 0;
}

TYPE FUNCTION(TYPE PARAMETER1, TYPE PARAMETER2, ..) {
    //do something...
    
    return SOMETHING;
}

int func(int a, int b) {
    int c = a+b;
    return c; 
}

int main() {
    int ans;
    ans = func(5, 6);
    cout << ans;
}

//Output: 11

void func() {
    cout << "HelloHa";
}

int main() {
    cout << func();
}

//Output: HelloHa

#include<iostream>
using namespace std;

??? max() {
    //???
    return ??;
}

int main() {
    //???
    cout << ??;
    return 0;
}

#include <iostream>
#include <algorithm> // sort, max, swap
#include <cmath> // sqrt
using namespace std;

int main(){
  int a = 9, b = 10, arr[3] = {0, 3, 2};
  sort(arr,arr+3);
  cout << arr[2] << endl; // 3
  cout << max(a, b) << endl; // 10
  swap(a, b);
  cout << a << endl; // 10
  cout << sqrt(b) << endl; //3 
}

int fac(int n){
    if(n==1)return 1;
    else return n*fac(n-1);
}

cout<<fac(5);

int F(int n){
    if(n==0)return 0;
    if(n==1)return 1;
    else return F(n-1)+F(n-2);
}

cout<<F(5);

cout<<gcd(34,10);

cout<<gcd(10,34);

#include <iostream>
using namespace std;
??? sum(){
    if(???)???;
    else return ???;
}
int main(){
    ???;
    cout<<???;
    return 0;
}

int a = 5;

int a = 5;

#include<iostream>
using namespace std;

int main(){
    int a;
    cout << &a;  //(maybe)0x70fe1c a的記憶體位址
    return 0;
}

#include<iostream>
using namespace std;

int main(){
    int a;
    int *p;
    p = &a;
    cout << p;   //(maybe)0x70fe1c 一樣是a的記憶體位址
    return 0;
}

#include<iostream>
using namespace std;

int main(){
    int a = 5;
    int *p = &a;
    cout << *p;   //5 
    //取記憶體P的值，也就是取a記憶體&a的值，也就是5
    return 0;
}

#include<iostream>
using namespace std;

int main(){
    int a = 5;
    int *p = &a;
    *p = *p+1;
    cout << a;   //6 
    //改記憶體P的值，也就是取a記憶體&a的值，也就是把5改成5+1=6
    return 0;
}