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' 我需要能够创建一个字母树。'.'然后用,'-'和.打开一个示例 .txt 文件'/' '//'。'.'转到树的左侧，或者在这种情况下是 rist 字母。'-'向右破折号。 http://www.skaut.ee/?jutt=10201 - 树长什么样。'

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

struct MorsePuu {
       char t2ht; 
       struct MorsePuu *punkt, *kriips, *next;
};

static int i;    
char TAHED[32]={' ','E','I','S','H','V','U','F','Ü','A','R','L','Ä','W','P','J','T','N','D','B','X','K','C','Y','M','G','Z','Q','O','Ö','™'};
//creating the "alphabet-tree"
struct MorsePuu *Ehitamine(int N) {
   struct MorsePuu *uus;
   int nl, nr;
   if (N==0) {return NULL;}
   else {
        nl = N / 2;
        nr = N-nl-1;
        uus = malloc(sizeof *uus);
        uus->t2ht = TAHED[i];
        i++;
        uus->punkt = NULL;
        uus->kriips = NULL;
        uus->punkt = Ehitamine(nl);
        uus->kriips = Ehitamine(nr);
        return uus;
        }
 }
 //creating the order of the tree.
  Preorder(struct MorsePuu *JViit) {
    printf("%c",JViit->t2ht);
    if (JViit->punkt != NULL) {
       Preorder(JViit->punkt);}
//      printf("%c",JViit->t2ht); Siin oleks Inorderi väljatrükk
    if (JViit->kriips != NULL) {
       Preorder(JViit->kriips);}
//      printf("%c",JViit->t2ht);  Ja siin oleks Postorderi väljatrükk
 }



main(void) {
    struct MorsePuu *morse, *abi;    
    char rida[128];
    FILE *fm=NULL;

    printf("Käigepealt tuleb morsepuu ?les ehitada!");
    i = 0;
    morse=Ehitamine(31);
    printf("Puu väljatrükk preorder järjekorras.\n");
    Preorder(morse);
    printf("%c",morse);

    //opening the file . Contents e.g .-/.// return ie. // stops it.
    fm = fopen("morse1.txt", "r");


    fgets(rida, 128, fm);
    printf("\n %s", rida);    

    fclose(fm);
    //this is where the reading and changing loop crashers.
    /*  
    for(i=0; i<strlen(rida); i++){
       if(rida[i]=='/'){

      }
       if(rida[i] == '.'){
          //printf();
          abi=abi->punkt;     
       }
       if(rida[i]== '-'){
          abi=abi->kriips;          
         }
      }
  */ 
  }

问题从最后一个循环开始。字母树已创建，但我无法从树中搜索字母。

4

1 回答 1

1

你没有为*abi这里分配任何内存

main(void) {
struct MorsePuu *morse, *abi;    
char rida[128];
FILE *fm=NULL;

Abi 是一个指向 struct MorsePuu 的指针，它指向一个随机位置，当您稍后使用它时，您会在 line 处导致未定义的行为abi=abi->punkt。

您必须添加一行

abi = malloc( sizeof( struct MorsePuu )) ;
于 2013-04-01T16:43:11.613 回答