动态字符串结构的一些算法实现

 

先把字符串的所有操作的函数和数据结构写出来

###################################DString.h##################################

//**********************FileName: DString.h********************/#include <stdio.h>#include <string.h>#include <stdlib.h>#include <malloc.h>typedef struct {char *str;int maxLength;int length;}DString;/*初始化*/void Initiate(DString *S, int max, char *string){int i;S->str = (char *)malloc(sizeof(char) * max);S->maxLength = max;for(i = 0; i < S->maxLength; i++){S->str[i] = '/0';}S->length = strlen(string);for(i = 0; i < S->length; i++){S->str[i] = string[i];}}/*插入子串*/int Insert(DString *S, int pos, DString T){int i;if(pos < 0){printf("参数pos错误！");return 0;}if( (S->length + T.length) > S->maxLength){S->str = (char *)realloc(S->str,(S->length + T.length)*sizeof(char)); //重新分配内存S->maxLength = S->length + T.length;}for(i = S->length-1; i >= pos; i--){ //向后移懂S->str[i+T.length] = S->str[i];}for(i = 0; i < T.length; i++){ //插入S->str[pos+i] = T.str[i];}S->length += T.length; //重置个数S->str[S->length] = '/0';return 1;}//删除数据块int Delete(DString *S, int pos, int len){int i;if(S->length <= 0){printf("空串");return 0;}else if( (pos < 0)||(len < 0)|| (pos+len) > S->length){printf("参数pos和len不合法!");return 0;}else{for(i = pos + len; i <= S->length - 1; i++){S->str[i - len] = S->str[i];}S->length = S->length - len;S->str[S->length] = '/0';return 1;}}//取子串int SubString(DString *S, int pos, int len, DString *T){int i;if( (pos < 0) || (len < 0) || (pos+len) > S->length){printf("参数pos和len错误！");return 0;}if(len > T->maxLength){T->str = (char *)malloc(len*sizeof(char));//重新分配内存T->maxLength = len;}for( i = 0; i < len; i++){T->str[i] = S->str[pos + i];}T->length = len;T->str[T->length] = '/0';return 1;}void Destory(DString *S){free(S->str);S->length = 0;S->maxLength = 0;} 

以上是串的几个最基本的操作，包括了初始化void Initiate(DString *S, int max, char *string), 插入：int Insert(DString *S, int pos, DString T)， 删除:int Delete(DString *S, int pos, int len),取子串int SubString(DString *S, int pos, int len, DString *T);和回收串的内存空间的操作。

下面是测试函数:::

###################################testDString.c################################

 

//*****************FileName：testDString.c************//#include <stdio.h>#include <malloc.h>#include "DString.h"int main(void){DString myString1, myString2, myString3;int i, max1 = 5, max2 = 9, max3 = 0;Initiate(&myString1, max1, "DATA");Initiate(&myString2, max2, "Structure");Initiate(&myString3, max3, "/0");printf("初始化myString2: ");//for(i = 0; i < myString2.length; i++){printf("%s", myString2.str);//}printf(" maxLengh = %d", myString2.maxLength);printf(" length = %d/n", myString2.length);Insert(&myString2, 0, myString1);printf("插入子串后： ");//for(i = 0; i < myString2.length; i++){printf("%s", myString2.str);//}printf(" maxLengh = %d", myString2.maxLength);printf(" length = %d/n", myString2.length);Delete(&myString2, 0, 5);printf("删除之后: ");//for(i = 0; i < myString2.length; i++){printf("%s", myString2.str);//}printf(" maxLengh = %d", myString2.maxLength);printf(" length = %d/n", myString2.length);SubString(&myString2, 1, 5, &myString3);printf("取出子串后: ");//for(i = 0; i < myString3.length; i++){printf("%s", myString3.str);//}printf(" maxLengh = %d", myString3.maxLength);printf(" length = %d/n", myString3.length);Destory(&myString3);Destory(&myString2);Destory(&myString1);} 

###################################end#####################################