C language rehabilitation training-2
//Binary ordered array search
int find(int arr1[], int k, int sz)
{
int left = 0;
int right = sz - 1;
while (left <= right)
{
int mid = (left + right) / 2;
if (k > arr1[mid])
{
left = mid + 1;
}
else if (k < arr1[mid])
{
right = mid - 1;
}
else
{
return k;
}
}
if (left > right)
{
return 0;
}
}
int main()
{
int arr1[] = {
1,2,3,4,5,6,7,8,9,11,12,13,23 };
int a = 0;
int k = 1;
int sz = sizeof(arr1) / sizeof(arr1[0]);
a = find(arr1, k, sz);
if (a == 0)
{
printf("未找到您所需的数字\n");
}
else
{
printf("您想要的数字在第%d位", a);
}
return 0;
}
//Accept an integer value (unsigned) and print each bit of it in sequence. For example, input 1234 and output 1 2 3 4
///1234%10 remainder 4. Then continue to modulate 10 and you will get other remainders 3 2 1
//The approach here is good but not particularly good
//Use recursion to convert a complex Let’s simplify the problem first
// We design a function named print
// Suppose the number to be printed is 1234, we first split it into (123) 4 || (12) 3 4 || (1) 2 3 4
void print(int n)
{
if (n > 9)
{
print(n / 10);
}
printf("%d\n", n % 10);
}
//举个例子就2位 ，递归的意思就是不停的用自身完成简化目的
//我先输入19 第一次进入大于9 ，那么先取一个高位1，再对1 进行操作，
///1进行了一个完整的print操作，最后输出了一个1 .而做完这次之后。下面还
//留有一个printf用来打印9 所以这个方法好
int main()
{
unsigned int num = 0;
scanf("%d", &num);
print(num);
return 0;
}
// factorial call of n
int jiecheng(int a)
{
int b = 0;
int sum = 1;
for (b = 1;b <= a;b++)
{
sum = sum * b;
}
return sum;
}
int main()
{
printf("请输入想要输入的数字");
int a = 0;
scanf("%d", &a);
int b = jiecheng(a);
printf("结果是%d", b);
return 0;
}
//Recursive ideas about factorial
//Factorial call of n
#include<stdlib.h>
int jiecheng(int a)
{
if (a > 1)
{
return a * jiecheng(a - 1);
}
else
return 1;
}
int main()
{
printf("请输入想要输入的数字");
int a = 0;
int b = 0;
scanf("%d", &a);
b = jiecheng(a);
printf("结果是%d", b);
return 0;
}
//bubble sort method
void paixu(int arr[], int sz)
{
int i = 0;
int j = 0;
int temp = 0;
for (i = 0;i < sz;i++)
{
for(j=0;j<=i;j++)
if (arr[j] < arr[i])
{
temp = arr[i];
arr[i] = arr[j];
arr[j] = temp;
}
}
}
int main()
{
int arr1[] = {
9,8,7,6,5,4,3,11,2,45,2,12222,23456 };
int a = 0;
int sz = sizeof(arr1) / sizeof(arr1[0]);
paixu(arr1, sz);
for (a = 0;a < sz;a++)
{
printf("%d\n", arr1[a]);
}
return 0;
}