#include <stdio.h>
int main()
{
	int i = 1;
	do
	{
		printf("%d ",i);
		i++;
	} while (i <= 10);
	return 0;
}

#include <stdio.h>
int main()
{
	int i = 1;
	do
	{
		if (i == 5)
			break;
		printf("%d ",i);
		i++;
	} while (i <= 10);
	return 0;
}

int main()
{
	int n = 0;
	int i = 0;
	int mux = 1;
	scanf("%d",&n);
	for (i = 1; i<n; i++)
	{
		mux *= (i + 1);
	}
	printf("mux = %d ",mux);
	return 0;
}

int main()
{
	int i = 0;
	int n = 0;
	int mux = 1;
	scanf("%d",&n);
	while (i < n)
	{
		i++;
		mux *= i;
	}
	printf("mux=%d",mux);
	return 0;
}

int main()
{
	int i = 0;
	scanf("%d", &i);
	int mux = i;
	do 
	{
		mux *= (i-1);
		i--;
		if (i != 1)
			continue;
		printf("mux=%d ", mux);
	} while ((i -1) != 0);
	return 0;
}

//其實(shí)是循環(huán)嵌套
int main()
{
	int m = 0;
	int i = 0;
	int mux = 1;
	int sum = 0;
	for (m = 1; m < 5; m++)
	{
		for (i = 1; i <=  m; i++)
		{
			mux *= i ;
		}
		//printf("mux = %d\n",mux);
		sum += mux;
	}
	printf("sum = %d",sum);
	return 0;
}

mux = 1;//在第二個(gè)for語(yǔ)句上面加上這條語(yǔ)句
//意思是在每一次求階乘之前，讓mux的初始值為1

//相對(duì)于上一段代碼，這段代碼更高效。
int main()
{
	int i = 0;
	int mux = 1;
	int sum = 0;
	for (i = 1; i <=  3; i++)
	{
		mux *= i ;
		sum += mux;
	}
	printf("sum = %d",sum);
	return 0;
}

int main()
{
	int arr[] = {1,2,3,4,5,6,7,8,9,10};
	int k = 7;//要查找的數(shù)字
	//在arr這個(gè)有序數(shù)組中查找k的值
	int sz = sizeof(arr) / sizeof(arr[0]);//求出數(shù)組的元素個(gè)數(shù)以此來(lái)確定查找范圍的下標(biāo)右值
	int left = 0;
	int right = sz - 1;
	int mid;
	while (left <= right)
	{
		int mid = (left + right) / 2;//第一次進(jìn)來(lái)的時(shí)候，數(shù)組元素中間值是arr[4]
		if (arr[mid] < k)
		{
			left = mid + 1;//范圍舍去左邊一半，從arr[5]開(kāi)始
		}
		else if (arr[mid] > k)
		{
			right = mid - 1;//范圍舍去右半邊，到arr[3]結(jié)束
		}
		else
		{
			printf("找到了，下標(biāo)為:%d\n",mid);
			break;//找到元素之后就跳出循環(huán)
		}
	}
	if (left > right)
	{
		printf("找不到\n");
	}
	return 0;
}

//比如打印 welcome to xi'an!!!
//         *******************
// 每一次打印的時(shí)候都放進(jìn)去一對(duì)字符替換掉**
//第一次打?。簑************！
//第二次打?。簑e**********!!
#include <string.h>
#include <stdio.h>
int main()
{
	char arr1[] = "welcome to xi'an!!!";
	char arr2[] = "*******************";
	int left = 0;
	int right = strlen(arr1) - 1;
	while (left <= right) 
	{
		arr2[left] = arr1[left];
		arr2[right] = arr1[right];
		printf("%s\n",arr2);
		left++;
		right--;
	}
	return 0;
}

#include <string.h>
#include <stdio.h>
#include <Windows.h>
int main()
{
	char arr1[] = "welcome to xi'an!!!";
	char arr2[] = "*******************";
	int left = 0;
	int right = strlen(arr1) - 1;
	while (left <= right) 
	{
		arr2[left] = arr1[left];
		arr2[right] = arr1[right];
		printf("%s\n",arr2);
		Sleep(1000);//1000毫秒，也就是1秒，這樣我們就可以看到它逐步打印的過(guò)程了
		system("cls");//清空屏幕
		left++;
		right--;
	}
	return 0;
}

#include <string.h>
#include <stdio.h>
int main()
{
	char arr[20] = { 0 };
	//假設(shè)正確的密碼是字符串“2022”，如何比較呢
	int m = 0;
	for (m = 0; m < 3; m++)
	{
		printf("請(qǐng)輸入密碼：");
		scanf("%s", arr);
		//if (arr == "2022")//這樣的寫法是錯(cuò)誤的，兩個(gè)字符串比較不能使用==來(lái)比較
		//應(yīng)該使用字符串函數(shù)strcmp
		if(strcmp(arr,"2022")==0)
		{
			printf("密碼正確\n");
			printf("進(jìn)入系統(tǒng)");
			break;
		}
			else
			{
				printf("密碼錯(cuò)誤\n");
			}
	}
	if (m == 3)
	{
		printf("退出系統(tǒng)\n");
	}
	return 0;
}

#define _CRT_SECURE_NO_WARNINGS
#include <stdlib.h>
#include <stdio.h>
void menu()
{
	printf("***********************\n");
	printf("***********************\n");
	printf("******  1.play  *******\n");
	printf("********0.exit*********\n");
	printf("***********************\n");
	printf("***********************\n");
}
void game()
{
	//猜數(shù)字游戲，將猜數(shù)字的功能封裝到這個(gè)game函數(shù)里面去
	//先生成隨機(jī)數(shù)，用rand函數(shù)，它需要的頭文件是stdlib.h
	//srand(100);
	//srand((unsigned int)time(NULL));
	//時(shí)間---時(shí)間戳，時(shí)間轉(zhuǎn)換出來(lái)的一個(gè)數(shù)字
	//（此時(shí)的時(shí)間相較于計(jì)算機(jī)的起始時(shí)間之間的差值，換算成以秒為單位的數(shù)字）
	//用time函數(shù)(需要包含頭文件time.h)來(lái)獲取時(shí)間戳,time函數(shù)的返回類型是time_t,而time_t是64位的整型
	//srand需要的是unsigned int 類型，那就將time的類型強(qiáng)制轉(zhuǎn)換一下
	//int random = rand();
	//查詢資料，可以發(fā)現(xiàn)rand函數(shù)返回了一個(gè)0-32767之間的數(shù)字
	//但是這個(gè)數(shù)字不夠隨機(jī) 要在調(diào)用rand之前使用srand功能去設(shè)置隨機(jī)數(shù)的生成器
	int random = rand() % 100 + 1;//%100的余數(shù)是0-99，再+1就是1-100
	printf("%d\n", random);
	int guess = 0;
	while (1)
	{
		printf("猜數(shù)字：");
		scanf("%d", &guess);
		if (guess < random)
		{
			printf("猜小了\n");
		}
		else if (guess > random)
		{
			printf("猜大了\n");
		}
		else
		{
			printf("猜對(duì)了，恭喜\n");
			break;
		}
	}
}
int main()
{
	int input = 0;
	srand((unsigned int)time(NULL));
	do
	{
		menu();//打印菜單
		printf("請(qǐng)選擇：");
		scanf("%d", &input);
		switch (input)
		{
		case 1:
			//printf("猜數(shù)字\n");
			game();
			break;
		case 0:
			printf("退出游戲");
			break;
		default:
			printf("輸入錯(cuò)誤，請(qǐng)重新選擇");
			break;
		}
	} while (input);
	return 0;
}