Preface

This blog will lead you to write some by yourself C Language games ; To increase for C Interest in language

One 、 Guess the number game

First of all, let's briefly introduce this little game ：
Usually played by two people , One side gives numbers , Guess one side . The person who gives the number should think of a number without repetition , You can't let the guessing know . The guessing person can start to guess .
If the correct answer is 576, And the guesser guessed 56, Then we can give the guesser a hint , Tell him to guess small ; If the guesser guesses for 999, Then we can give the guesser a hint , Tell it to guess big ; Until you get it right ;.
analysis ：
1、 Since you need to guess the number , We players can't know , The computer has to randomly generate a value for us to guess ;
2、 Since random values are needed , We can call rand（） Function to generate random values ;

rand The range of random numbers that can be generated is 0~RAND_MAX;
RAND_MAX How much is? ？

So let's test , See if it can really generate random numbers ;


After many tests , Find out rand Always generate 41, It hasn't changed , No random number is generated ; This is very puzzling ,rand Is the generated random number really ？
actually ,rand The function is for a function called “ seeds ” To generate a random number . The reason why the same number is generated every time before , Because of rand The default seed constant of the function is 1. To generate different random numbers , You have to change the value of the seed ;
What changes this is the need srand Function to implement ;

Let's say we call srand（2）, It'll take 2 Generate random numbers for the benchmark ; But once the seed is determined , The generated random number is also determined ,

Therefore, we must change the seed value itself from a constant to a random number , However, in order to generate random numbers, we need random numbers , This in itself is contradictory ;
Our general solution is ： Take the time of running the program as the seed ;

It's useful here time function
A brief introduction ：

Running results ：


So far, we have solved the problem of how to generate random numbers ;
3、 How to control the scope ？
In order to reduce the difficulty of the game , We have to control the range of numbers generated by the residence ：
The general method only needs ：b+rand()%(a+1)// Generation is greater than or equal to b And less than or equal to b+a The random number ;
So far, the idea has been roughly straightened out ;
Next, we can implement it in code ：

#include<time.h>
#include<stdio.h>
enum GAME// Use enumeration constants to express , Make code more readable ;
{
    
	EXIT,// The default from the 0 Start , Then increase in turn 
	PLAY,

};
void menu()// Simply write a menu to give players a good interface ;
{
    
	printf("+*******  Guess the number game (1~100) *******+\n");
	printf("l************ 1.PLAY *************l\n");
	printf("l************ 0.EXIT *************l\n");
	printf("+*********************************+\n");
}
void game()
{
    
	int key = rand() % 100 + 1;// Generate 1~100 The random number 
	int val = 0;// The number we guessed ;
	while (1)// Using the dead loop , Give players the chance to guess wirelessly ;
	{
    
		printf(" Please enter :");
		scanf("%d",&val);
		if (key > val)
			printf(" Guess a little \n");

		else if (key < val)
			printf(" Guess the \n");
		else
		{
    
			printf(" Congratulations on your guesses \n");
			break;
		}
	}
}
int main()
{
    
	srand((unsigned int)time(NULL));
	int input = 0;
	do
	{
    
		menu();
		scanf("%d",&input);
		switch (input)
		{
    
		case PLAY:
			game(); break;
		case EXIT:printf(" Quit the game \n"); break;
		default:printf(" Input error , Please reselect \a\a\a\n"); break;
		}
	} while (input);
	return 0;
}

Two 、 Rotate the cursor

Next, let's write a little game ;
Rotate the cursor ;
design sketch ;

It is this cursor that keeps rotating ;
Ideas ： Mainly used \r This escape character , The Chinese name is return ;
\r and \n The difference between ？
\r： The Chinese name is return , The function is to move the cursor to the beginning of the line , Write from scratch ;
\n： Chinese name is newline , The function is to move the cursor to the beginning of the next line , Write from scratch ;
With this knowledge , Rotating the cursor is a good implementation ：

#include<windows.h>
int main()
{
    
	int i = 0;
	char arr[] = "|/-|\\";// here \\ Represents a character \ while (1)
	{
    
		i %= 5;// Prevent arrays from crossing bounds ;
		printf("[%c]\r",arr[i]);
		i++;
		Sleep(300);// Let the program rest 0.3s
	}

	return 0;
}

3、 ... and 、 Multiple characters move from both ends , Converging in the middle

The last little game , It's similar to rotating the cursor ;
design sketch ：

* Will disappear one by one ;

Go straight to the code ：

#include<windows.h>
int main()
{
    
	char arr1[] = "I love China!";//1
	char arr2[] = "*************";//2  The two character arrays must be the same length to be effective ;
	int left = 0;
	int right = strlen(arr1) - 1;
	printf("%s\r", arr2);
	Sleep(1000);
	while (left<=right)
	{
    
		arr2[left] = arr1[left];
		arr2[right] = arr1[right];
		right--;
		left++;
		printf("%s\r",arr2);
		Sleep(1000);
	}
	printf("%s", arr2);// Prevent the last carriage return I Ate ;
	return 0;
}