c - 在 C 中使用字符串数组

Question

我试图将字符串存储在数组中。但是有一个错误。我的代码在这里:

#include <stdio.h>
#include <string.h>
#include <math.h>
#include <malloc.h>

const long long max_size = 2000;         // max length of strings
const long long N = 40;                  // number of closest words that will be shown
const long long max_w = 50;              // max length of vocabulary entries

int main(int argc, char **argv) {
  FILE *f;
  char st1[max_size];
  char kelimeler[max_size];     
  char *kelimelerim[max_size];  //string array initialization here
  char *bestw[N];
  char file_name[max_size], st[100][max_size];
  float dist, len, bestd[N], vec[max_size];
  long long words, size, a, b, c, d, cn, bi[100];
  char ch;
  float *M;
  char *vocab;

  strcpy(file_name, argv[1]);
  f = fopen(file_name, "rb");
  if (f == NULL) {
    printf("Input file not found\n");
    return -1;
  }


  fscanf(f, "%lld", &words);
  fscanf(f, "%lld", &size);
  vocab = (char *)malloc((long long)words * max_w * sizeof(char));
  for (a = 0; a < N; a++) bestw[a] = (char *)malloc(max_size * sizeof(char));
  M = (float *)malloc((long long)words * (long long)size * sizeof(float));
  if (M == NULL) {
    printf("Cannot allocate memory");
    return -1;
  }

  for (b = 0; b < words; b++) {
    a = 0;
    int sayac=0;
    while (1) {
      sayac++;  
      vocab[b * max_w + a] = fgetc(f);
      if (feof(f) || (vocab[b * max_w + a] == ' ')) {

        strcpy(kelimeler,&vocab[b * max_w + a-sayac+2]);  //gets the string here
        kelimelerim[b] = kelimeler;                      //and store it into string array here
        printf("%s %lld\n",kelimelerim[b],b); 
        sayac=0;
        break;

      }
      if ((a < max_w) && (vocab[b * max_w + a] != '\n')) 
        a++;
    }
    vocab[b * max_w + a] = 0;
    for (a = 0; a < size; a++) 
    fread(&M[a + b * size], sizeof(float), 1, f);
    len = 0;
    for (a = 0; a < size; a++) 
    len += M[a + b * size] * M[a + b * size];
    len = sqrt(len);
    for (a = 0; a < size; a++) 
    M[a + b * size] /= len;
  }
  fclose(f);

  int index;
  for (index = 0; index < words; index ++){
      printf("%s %d \n",kelimelerim[index ], index );
  }
  // here, the loop prints last string stored into array, for all indexes.       

我删除了不重要的行。当我运行上面的代码并打印 kelimelerim 数组时，会为数组的所有索引打印最后一个字符串。我的错误在哪里？你能帮帮我吗？

Answer 1

你永远不会初始化vocab，所以下面有undefined behaviour :

  vocab[b * max_w + a] = fgetc(f);

从那时起，所有的赌注都落空了。