C

函数与指针

#include <stdio.h>

double min(double x, double y);
void chline(char ch[], int  i, int j);
void to_binary(int i);
long fibonacci(int n);
void swap(int* a, int* b);


int main()
{
	printf("计算最小值(2.0,2.01) = %5.2f 
", min(2.0, 2.01));
	char ss[50] = "beautiful";
	printf("指定输出 beautiful 1,3 = ");
	chline(ss, 1, 3);
	printf("
 10进制转2进制: 100 =");
	to_binary(100);

	printf("
 打印斐波那契数列第n个:");
	long fb = fibonacci(5);
	printf("fb = %ld 
 ", fb);

	printf("通过指针交换 
");
	int a = 1, b = 2;
	printf("before, a=%d ,b=%d 
", a, b);
	swap(&a, &b);
	printf("after , a=%d ,b=%d 
", a, b);

	return 0;
}

double min(double x, double y)
{
	return x < y ? x : y;
}

void chline(char ch[], int i, int j)
{
	for (; i <= j; i++) {
		printf("%c", ch[i]);
	}
	printf("
");
}

void to_binary(int i)
{
	int mod = i % 2;
	int shang = i / 2;
	if (1 == shang)printf("%d", shang);
	else if (shang > 1)to_binary(shang);
	printf("%d", mod);
}

long fibonacci(int n)
{
	if (n > 2) 
		return fibonacci(n - 1) + fibonacci(n - 2);
	return 1;
}

void swap(int * a, int * b)
{
	int* temp;
	temp = *a;
	*a = *b;
	*b = temp;
}

数组与指针

#include <stdio.h>

printf_array(int array[][3], int row, int col);
printf_vla(int rows, int cols, int ar[rows][cols]); // 变长数组VLA ,C99支持

int main()
{
	int days[] = { 1,3,10 };
	for (int i = 0; i < sizeof days / sizeof days[0]; i++)
		printf("index : %d , value : %d 
", i, days[i]);

	int matrix1[2][3] = {
		{1,2,3},
		{1,4,3}
	};
	 // 二维数组打印
	printf_array(matrix1, 2, 3);
	
	return 0;
}

printf_array(int array[][3], int row, int col)
{
	for (int i = 0; i < row; i++)
	{
		for (int j = 0; j < col; j++)
		{
			printf("%d,", *(*(array + i) + j));
		}
		printf("
");
	}

}