C/C++_定番ハンズオン7選_2025

01_helloworld.cpp

#include <cstdlib>
#include <stdio.h>
#include <string>
#include <ctime>
#include <iostream>

/*
	1, $brew install cmake
	2, $cmake --version
	3, $ cd your_project_folder
	4, $mkdir build
	5, $cd build
	6, $cmake ../
	7, $make
	8, $./test
*/

using namespace std;

int main(int argc, char* argv[]){

	cout << "== Hello, World!! ==" << endl;

	string input;

	cout << "名前を入力してください" << endl;
	if(cin >> input){
		cout << "こんにちは, " << input << "さん!!" << endl;
	}

	cout << "年齢を入力してください" << endl;
	if(cin >> input){
		const int num = stoi(input);
		if(num < 13){
			cout << "少年です!!" << endl;
		}else if(num < 18){
			cout << "青年です!!" << endl;
		}else if(num < 30){
			cout << "成人です!!" << endl;
		}else if(num < 65){
			cout << "中年です!!" << endl;
		}else{
			cout << "高齢です!!" << endl;
		}
	}

	cout << "1 ~ x までの値の合計値を計算します" << endl;
	if(cin >> input){
		const int num = stoi(input);
		int total = 0;
		for(int i=0; i<num; i++){
			total += i + 1;
		}
		cout << "合計値は" << total << "です" << endl;
	}

	return EXIT_SUCCESS;
}

02_dice.cpp

#include <cstdlib>
#include <stdio.h>
#include <string>
#include <ctime>
#include <iostream>

#include "conio.h"

/*
	1, $brew install cmake
	2, $cmake --version
	3, $ cd your_project_folder
	4, $mkdir build
	5, $cd build
	6, $cmake ../
	7, $make
	8, $./test
*/

using namespace std;

void dice(int index){

	if(index == 1){
		cout << "+-------+" << endl;
		cout << "|       |" << endl;
		cout << "|   ●   |" << endl;
		cout << "|       |" << endl;
		cout << "+-------+" << endl;
		return;
	}
	if(index == 2){
		cout << "+-------+" << endl;
		cout << "|     ● |" << endl;
		cout << "|       |" << endl;
		cout << "| ●     |" << endl;
		cout << "+-------+" << endl;
		return;
	}
	if(index == 3){
		cout << "+-------+" << endl;
		cout << "|     ● |" << endl;
		cout << "|   ●   |" << endl;
		cout << "| ●     |" << endl;
		cout << "+-------+" << endl;
		return;
	}
	if(index == 4){
		cout << "+-------+" << endl;
		cout << "| ●   ● |" << endl;
		cout << "|       |" << endl;
		cout << "| ●   ● |" << endl;
		cout << "+-------+" << endl;
		return;
	}
	if(index == 5){
		cout << "+-------+" << endl;
		cout << "| ●   ● |" << endl;
		cout << "|   ●   |" << endl;
		cout << "| ●   ● |" << endl;
		cout << "+-------+" << endl;
		return;
	}
	if(index == 6){
		cout << "+-------+" << endl;
		cout << "| ●   ● |" << endl;
		cout << "| ●   ● |" << endl;
		cout << "| ●   ● |" << endl;
		cout << "+-------+" << endl;
		return;
	}
}

int main(int argc, char* argv[]){
	
	srand((unsigned)time(NULL));

	const int total = 6;

	cout << "== サイコロ ==" << endl;
	while(true){
		cout << "SPACE: サイコロを振る, q: 終了" << endl;

		// Keyboard
		const char key = getch();
		if(key == 'q') break;

		// Dice
		const int num = rand() % total + 1;
		dice(num);
	}

	return EXIT_SUCCESS;
}

03_omikuji.cpp

#include <cstdlib>
#include <stdio.h>
#include <string>
#include <ctime>
#include <iostream>

#include "conio.h"

/*
	1, $brew install cmake
	2, $cmake --version
	3, $ cd your_project_folder
	4, $mkdir build
	5, $cd build
	6, $cmake ../
	7, $make
	8, $./test
*/

using namespace std;

int main(int argc, char* argv[]){

	srand((unsigned)time(NULL));

	const string OMIKUJI[] = {"大吉", "中吉", "小吉", "吉", "末吉", "凶", "大凶"};
	const int total = sizeof(OMIKUJI) / sizeof(string);

	cout << "== おみくじ ==" << endl;
	while(true){
		cout << "SPACE: おみくじを引く, q: 終了" << endl;

		// Keyboard
		const char key = getch();
		if(key == 'q') break;

		// Omikuji
		const int index = rand() % total;
		cout << "結果: " << OMIKUJI[index] << endl;
	}

	return EXIT_SUCCESS;
}

04_find_number.cpp

#include <cstdlib>
#include <stdio.h>
#include <string>
#include <ctime>
#include <iostream>

#include "conio.h"

/*
	1, $brew install cmake
	2, $cmake --version
	3, $ cd your_project_folder
	4, $mkdir build
	5, $cd build
	6, $cmake ../
	7, $make
	8, $./test
*/

using namespace std;

int str2num(const string &str){
	int num = -1;
	try{
		num = stoi(str);
	}catch(const invalid_argument& e){
		return num;
	}catch(const out_of_range& e){
		return num;
	}
	return num;
}

int main(int argc, char* argv[]){

	srand((unsigned)time(NULL));

	int counter = 0;
	int numMin = 0;
	int numMax = 10;
	int numAnswer = numMin + rand() % (numMax - numMin);
	//cout << "答え: " << numAnswer << endl;

	cout << "== 数当てゲーム ==" << endl;
	while(true){

		counter++;
		cout << "数字を当ててください: " << counter << "回目" << endl;
		cout << "ヒント: " << numMin << "から" << numMax << "までの範囲です" << endl;

		string strInput;
		if(cin >> strInput){
			const int numInput = str2num(strInput);
			if(numInput < numMin) continue;
			if(numMax < numInput) continue;
			if(numMin < 0) continue;

			if(numAnswer < numInput){
				cout << "残念、" << numInput << "より小さい数字です。" << endl;
				numMax = numInput - 1;
				continue;
			}

			if(numInput < numAnswer){
				cout << "残念、" << numInput << "より大きい数字です。" << endl;
				numMin = numInput + 1;
				continue;
			}

			if(numInput == numAnswer){
				cout << "正解です: " << numInput << endl;
				cout << "チャレンジ回数: " << counter << "回" << endl;
				break;
			}
		}
	}
	return EXIT_SUCCESS;
}

05_pyramid.cpp

#include <cstdlib>
#include <stdio.h>
#include <string>
#include <ctime>
#include <iostream>

#include "conio.h"

/*
	1, $brew install cmake
	2, $cmake --version
	3, $ cd your_project_folder
	4, $mkdir build
	5, $cd build
	6, $cmake ../
	7, $make
	8, $./test
*/

using namespace std;

int str2num(const string &str){
	int num = -1;
	try{
		num = stoi(str);
	}catch(const invalid_argument& e){
		return num;
	}catch(const out_of_range& e){
		return num;
	}
	return num;
}

void pyramidA(int height){
	cout << "== A:" << height << " ==" << endl;

	for(int r=0; r<height; r++){
		for(int c=0; c<r+1; c++){
			cout << "*";
		}
		cout << endl;
	}
}

void pyramidB(int height){
	cout << "== B:" << height << " ==" << endl;

	for(int r=0; r<height; r++){
		for(int c=0; c<height-r-1; c++){
			cout << " ";
		}
		for(int c=0; c<r+1; c++){
			cout << "*";
		}
		cout << endl;
	}
}

void pyramidC(int height){
	cout << "== C:" << height << " ==" << endl;

	const int width = height * 2 + 1;
	for(int r=0; r<height; r++){
		const int len = r * 2 + 1;// 1, 3, 5, 7...
		for(int c=0; c<(width-len)/2-1; c++){
			cout << " ";
		}
		for(int c=0; c<len; c++){
			cout << "*";
		}
		cout << endl;
	}
}

int main(int argc, char* argv[]){
	
	srand((unsigned)time(NULL));

	cout << "== ピラミッド ==" << endl;
	while(true){
		cout << "ピラミッドの高さを入力してください, q: 終了" << endl;

		string input;
		if(cin >> input){
			if(input.compare("q") == 0) break;

			const int height = str2num(input);
			if(height < 0) continue;
			pyramidA(height);
			pyramidB(height);
			pyramidC(height);
		}
	}

	return EXIT_SUCCESS;
}

06_janken.cpp

#include <cstdlib>
#include <stdio.h>
#include <string>
#include <ctime>
#include <iostream>

#include "conio.h"

/*
	1, $brew install cmake
	2, $cmake --version
	3, $ cd your_project_folder
	4, $mkdir build
	5, $cd build
	6, $cmake ../
	7, $make
	8, $./test
*/

using namespace std;

int str2num(const string &str){
	int num = -1;
	try{
		num = stoi(str);
	}catch(const invalid_argument& e){
		return num;
	}catch(const out_of_range& e){
		return num;
	}
	return num;
}

int main(int argc, char* argv[]){

	srand((unsigned)time(NULL));

	const string HANDS[] = {"グー", "チョキ", "パー"};
	const int total = sizeof(HANDS) / sizeof(string);

	int nWin = 0;
	int nLose = 0;
	int nEven = 0;

	cout << "== ジャンケンゲーム ==" << endl;
	while(true){
		cout << "選択してください" << endl;
		cout << "1: グー, 2: チョキ, 3: パー, q: 終了" << endl;

		// Keyboard
		const char key = getch();
		if(key == 'q') break;

		// Janken
		if(key == '1' || key == '2'|| key == '3'){
			const int nYou = key - '0';
			const int nCom = rand() % total + 1;
			cout << "You: " << HANDS[nYou - 1] << " vs ";
			cout << "Com: " << HANDS[nCom - 1] << endl;
			const int result = (nCom - nYou + 3) % 3;
			if(result == 1){
				cout << "結果: 勝ちました" << endl;
				nWin++;
			}else if(result == 2){
				cout << "結果: 負けました" << endl;
				nLose++;
			}else{
				cout << "結果: あいこです" << endl;
				nEven++;
			}
			cout << "成績: ";
			cout << "Win(" << nWin << "), ";
			cout << "Lose(" << nLose << "), ";
			cout << "Even(" << nEven << ")" << endl;
		}
	}

    return EXIT_SUCCESS;
}

07_typing_game.cpp

#include <cstdlib>
#include <stdio.h>
#include <string>
#include <ctime>
#include <iostream>

#include "conio.h"

/*
	1, $brew install cmake
	2, $cmake --version
	3, $ cd your_project_folder
	4, $mkdir build
	5, $cd build
	6, $cmake ../
	7, $make
	8, $./test
*/

using namespace std;

int main(int argc, char* argv[]){
	
	srand((unsigned)time(NULL));

	const string words[] = {"abc", "def", "ghi", "jkl", "mno"};
	const int total = sizeof(words) / sizeof(string);
	int index = 0;
	int score = 0;

	cout << "== タイピングゲーム ==" << endl;
	cout << "文字を入力してください, q: 終了" << endl;
	while(true){
		cout << "[問" << index+1 << "/" << total << "] " << words[index] << ": ";

		string input;
		if(cin >> input){
			if(input.compare("q") == 0) break;
			if(input.compare(words[index]) == 0){
				cout << "GOOD!!" << endl;
				score++;
			}else{
				cout << "BAD..." << endl;
			}
		}

		index++;
		if(index < total) continue;
		break;
	}
	cout << "結果: " << score << "/" << total << "点" << endl;

	return EXIT_SUCCESS;
}

conio.h

#include <termios.h>
#include <unistd.h>
#include <stdio.h>
 
/* reads from keypress, doesn't echo */
int getch(void)
{
    struct termios oldattr, newattr;
    int ch;
    tcgetattr( STDIN_FILENO, &oldattr );
    newattr = oldattr;
    newattr.c_lflag &= ~( ICANON | ECHO );
    tcsetattr( STDIN_FILENO, TCSANOW, &newattr );
    ch = getchar();
    tcsetattr( STDIN_FILENO, TCSANOW, &oldattr );
    return ch;
}
 
/* reads from keypress, echoes */
int getche(void)
{
    struct termios oldattr, newattr;
    int ch;
    tcgetattr( STDIN_FILENO, &oldattr );
    newattr = oldattr;
    newattr.c_lflag &= ~( ICANON );
    tcsetattr( STDIN_FILENO, TCSANOW, &newattr );
    ch = getchar();
    tcsetattr( STDIN_FILENO, TCSANOW, &oldattr );
    return ch;
}