字符串链式存储结构的基本运算

/**
 *@Name:字符串链式存储结构的基本运算 
 *@Description:空串的创建,串初始化、遍历、元素的插入、删除和修改和移动。
 *@Author:Freedoman
 *@Date: 2014-8-12
 */
 
#include 
#include 
#include 

/*字符结点*/
struct Node{
	char c;
	struct Node * next;
};

typedef struct Node * PNode;

/*函数声明*/
PNode createNullLinkedString(void);
int isNullLinkedString(PNode pstr);
int initLinkedString(PNode pstr);
int insertBeforeElement(PNode pstr);
int dtempteElement(PNode pstr);
void printString(PNode pstr);

/*----------创建一个空的字符串---------------*/
PNode createNullLinkedString(){
	PNode pstr=(PNode)malloc(sizeof(struct Node));
	if(pstr != NULL){
		pstr->next=NULL;
		pstr->c='-';
		printf("创建成功！\n");
	}
	else{
		pstr=NULL;
		printf("创建失败！\n");
	}
	return pstr;
}

/*-----------判断串是否为空----------------*/ 
int isNullLinkedString(PNode pstr){
	if(pstr->next == NULL){
		printf("空串！\n");
		return 1;
	}
	else{
		printf("非空串！\n");
		return 0;
	}
}

/*----------初始化一个空字符串-------------*/
int initLinkedString(PNode pstr){
	PNode cur = pstr;
	
	if(isNullLinkedString(pstr)){
		
		while(1){
			char c;
			printf("输入字符(@结束)>>>");
			scanf("%c",&c);
			getchar();
			if(c =='@'){
				break;
			}
			// 申请要插入的结点 
			PNode temp = (PNode)malloc(sizeof(Node));
			temp->next = NULL;
			temp->c = c;
			if(pstr->next == NULL){
				pstr->next = temp;
				cur = pstr;
			}else{
				cur->next->next = temp;
				cur = cur->next;
			}	
		} 
		printf("初始化完毕！\n");
		printString(pstr);
		return 1;
	}else{
		printf("初始化失败！\n");
		return 0;
	}
}

/*-----------在指定字符之前插入字符---------------*/
int insertBeforeElement(PNode pstr,char c,char s){
	PNode cur = pstr;
	while(cur->next != NULL){
		// 找到指定字符 
		if(cur->next->c == c) { 
			PNode temp = (PNode)malloc(sizeof(PNode));
			temp->c = s;
			temp->next = cur->next;
			cur->next = temp; 
			printf("插入成功！\n");
			printString(pstr);
			return 1;
		}
		cur = cur->next;
	}
	printf("未找到指定字符，插入失败\n");
	return 0;
}

/*---------删除指定元素----------*/
int deleteElement(PNode pstr,char c){
	PNode cur = pstr;
	while(cur->next != NULL){
		// 找到指定字符 
		if(cur->next->c == c){
			cur->next = cur->next->next;
			printf("删除成功！\n");
			printString(pstr);
			return 1; 
		}
		cur = cur->next;
	}
	printf("删除失败！\n");
	return 0;
}

/*----------打印当前字符串----------*/
void printString(PNode pstr){
	PNode cur = pstr;
	
	printf("[");
	while(cur->next != NULL){
		printf(" %c ",cur->next->c);
		cur = cur->next;
	}
	printf("]");
}
/*-------主控-------*/
int main(void){
	PNode pstr= NULL;
	printf("\n--------字符串的基本操作---------\n");
	char c,s,ch;
	int input;
	while(1){
		printf("\n 1_创建空串\n 2_判断当前是否为空\n 3_初始化空串\n");
		printf(" 4_在指定字符之前插入字符\n 5_删除指定字符\n 6_打印串\n");
		printf("\n请选择>>>"); 
		scanf("%d",&input);
		scanf("%c",&ch); 
		switch(input){
			case 1 : 
				pstr = createNullLinkedString();
				break;
			case 2 : 
				isNullLinkedString(pstr);
				break;
			case 3 : 
				initLinkedString(pstr);
				break;
			case 4 : 
				printf("请指定字符>>>");
				scanf("%c",&c);
				getchar();
				printf("请输入要插入的字符>>>");
				scanf("%c",&s);
				insertBeforeElement(pstr,c,s);
				break;
			case 5 :
				printf("请指定字符>>>");
				scanf("%c",&s); 
				deleteElement(pstr,s);
				break;
			case 6 : 
				printString(pstr);
				break;
			default: 
				printf("输入错误,请重新输入");
			 	break;
		}
	}
	return 0;
}