7月11日 今日所学 整理分享

#define _CRT_SECURE_NO_WARNINGS 1

#include <stdio.h>

#include <string.h>


int Add(int x, int y)
{
	int z = 0;
	z = x + y;
	return z;
}

int main()
{
	int a = 30;
	int b = 50;
	int sum = Add(a , b);
	printf("%d\n", sum);
	return 0;
}










void Swap1(int x, int y)
{
	int tmp = 0;
	tmp = x;
	x = y;
	y = tmp;

}


void Swap2(int* pa, int* pb)
{
	int tmp = 0;
	tmp = *pa;
	*pa = *pb;
	*pb = tmp;

}

int main()
{
	int a = 40;
	int b = 80;
	printf("a = %d	b=%d\n", a, b);
	Swap1(a, b);//传值调用
	Swap2(&a, &b);//传址调用
	printf("a = %d	b=%d\n", a, b);
	return 0;
}












//当实参传给形参的时候
//形参其实是实参的一份临时拷贝
//对形参的改动不会影响实参

int get_max(int x, int y)
{
	if (x > y)
	{
		return x;
	}
	else
		return y;
}



int main()
{
	int a = 20;
	int b = 10;
	int max = get_max(a, b);
	printf("max = %d\n", max);

	return 0;

}













int is_prime(int n)
{
	int j = 0;
	for (j = 2; j < n; j++)
	{
		if (n%j == 0)
			return 0;
	}
	return 1;
}

int main()
{
	int i = 0;
	for (i = 100; i <= 200; i++)
	{
		if (is_prime(i) == 1)
			printf("%d ", i);		
	}
	return 0;
}















int is_leap_year(int n)
{
	if ((n % 4 == 0 && n % 10 != 0) || (n % 400 == 0))
		return 1;
	else
		return 0;
}



int main()
{
	int year = 0;
	int a = 0;
	for (year = 2000; year <= 3000; year++)
	{
		if (1 == is_leap_year(year))
		{
			printf("%d  ", year);
		}
	}	
	return 0;
}













int kkkk(int arr[], int  a, int se)
{
	int left = 0;
	int right = se - 1;
	while (left <= right)
	{
		int mid = (left + right) / 2;
		if (arr[mid] > a)
		{
			right = mid - 1;
		}
		else if (arr[mid] < a)
		{
			left = mid + 1;
		}
		else
		{
			return mid;
		}
			
	}
	return -1;
}

int main()
{
	int arr[] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };
	int a = 7;
	int se = sizeof(arr) / sizeof(arr[0]);
	int ret = kkkk(arr, a, se);
	if (ret == -1)
	{
		printf("找不到\n");
	}
	else
		printf("找到了，下标是  %d", ret);
	return 0;
}














void add(int* p)
{
	(*p)++;
}

int main()
{
	int i = 0;
	int num = 0;
	while (i<=3)
	{
		add(&num);
		printf("num = %d\n", num);
		i++;
	}
	return 0;
}

int main()
{
	printf("%d", printf("%d", printf("%d", printf("%d", printf("%d", 23)))));//链式结构
	return 0;
}