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gitee
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个人简介

作者是一个来自河源的大三在校生，以下笔记都是作者自学之路的一些浅薄经验，如有错误请指正，将来会不断的完善笔记，帮助更多的Java爱好者入门。

C语言数据结构与算法

BF和KMP算法

#include <stdio.h>


int slen(char* s)
{
	int i = 0;
	if (s == NULL) {
		return 0;
	}
	else {

		while (s[i] != '\0')
		{
			i++;
		}
		return i;
	}
}

//BF
int* bf(char* str,char *ptr)
{
	int i=0, j=0;
	int index = 0;
	int strlen = slen(str);
	int ptrlen = slen(ptr);


	while (i<strlen&&j<ptrlen)
	{

		if (str[i]==ptr[j]) {
			i++; 
			j++;
		}
		else {
			index++;
			i = index;
			j = 0;
		}
	}
	if (j == ptrlen) {
		return i-j;
	}
	else {
		return -1;
	}
	

}


//kmp
int* kmp(char* haystack, char* needle)
{
	int i = 0, j = 0;
	int strlen = slen(haystack);
	int ptrlen = slen(needle);

	while (i < strlen && j < ptrlen)
	{

		if (haystack[i] == needle[j]) {
			i++;
			j++;
		}
		else {
			i = i-j+1;
			j = 0;
		}
	}
	if (j == ptrlen) {
		return i - j;
	}
	else {
		return -1;
	}
}



int main(void)
{
	char *str= "hello";

	char* ptr = "ll";

	//int res=bf(str, ptr);

	int res = kmp(str, ptr);

	printf("%d \n",res);


	return 0;
}

循环链表

#include <stdio.h>
#include <stdlib.h>
#define true 1
#define false 0

//C语言实现循环链表

//链表结点
typedef struct Node {

	int data;
	struct Node* next;

} node;

typedef struct Node* linklist;

void initList(linklist head)
{
	printf("初始化循环链表......\n");
	if (head == NULL) {
		head = (node*)malloc(sizeof(node));
	}
	head->data = 0;
	head->next = head; //初始化给head的指针指向自己

}

//插入(尾插法)
void tailAddNode(linklist head,int data) {

	node* p = (node*)malloc(sizeof(node));
	p->next = head;
	node* newNode = (node*)malloc(sizeof(node));
	newNode->data = data;
	while (true) {

		if (p->next->next == head) { //当前p->next就是尾
			p->next->next = newNode;
			newNode->next = head;
			head->data++;
			printf("插入结点成功......\n");
			break;
		}
		else {
			p->next = p->next->next;
		}
	}
}



//删除
void deleteNode(linklist head,int index)
{
	node* p = (node*)malloc(sizeof(node));
	p->next = head;
	int cur = 0;
	//int in = index % (head->data); //in是取模后的下标
	while (true)
	{
		if ((cur+1)==index) //此时下一个结点就是我们要删除的结点
		{
			node* temp = p->next->next;

			p->next->next = p->next->next->next;
			head->data--;
			free(temp);
			printf("删除结点成功......\n");
			break;
		}
		else {
			p->next = p->next->next;
			cur++;
		}


	}

}

void printList(linklist head)
{
	node* p = (node*)malloc(sizeof(node));
	p->next = head->next;

	while (true) {

		if (p->next->next == head) {
			printf("%d ", p->next->data);
			printf("进入循环-> %d ", p->next->next->next->data);
			break;
		}
		else {
			printf("%d ",p->next->data);
			p->next = p->next->next;
		}

	}


}
int main(void)
{

	linklist head = (node*)malloc(sizeof(node));

	initList(head);

	tailAddNode(head, 15);

	tailAddNode(head, 22);

	tailAddNode(head, 33);

	printList(head);

	deleteNode(head,3);

	printList(head);

	return 0;

}

斐波那契和阶乘

#include <stdio.h>
#include <stdlib.h>

//递归题 easy

//1.斐波那契数列
int fib(int n) {

	if (n == 0)
	{
		return 0;
	}

	if (n == 1)
	{
		return 1;
	}
	 
		return fib(n - 1) + fib(n - 2);
 
}

//2.阶乘
int jiecheng(int n)
{
	 
	if (n==0||n == 1)
	{
		return 1;
	}
	else {

		return n * jiecheng(n - 1);
	}

}


int main(void)
{
	int res=jiecheng(10);
	printf("%d\n",res);

	return 0;

}