C语言中合并排序后字符串数组时程序崩溃，求技术解决方案

Hey there! Let's figure out why your merge step is crashing—since your bubble sort works perfectly, the problem is almost certainly tied to how you're handling memory for big_array or the logic in your merge loop. Here are the most common issues to check first:

1. Insufficient or Unsafe Memory Allocation for big_array #

• If you haven't allocated enough space for big_array to hold all elements from both DTA and DTB, or if you're using an uninitialized pointer to access it, this will cause an immediate crash.
• For dynamic allocation (the safest approach for variable-length arrays), make sure you're doing something like:

  int lenA = /* precomputed length of sorted DTA */;
  int lenB = /* precomputed length of sorted DTB */;
  int *big_array = malloc((lenA + lenB) * sizeof(int));
  // Always check if malloc succeeded!
  if (big_array == NULL) {
      printf("Memory allocation failed!\n");
      return 1;
  }
  

• If you're using a fixed-size stack array (e.g., int big_array[200];), double-check that the total number of elements in DTA and DTB doesn't exceed this fixed size—stack overflow will crash your program instantly.

2. Off-by-One Errors or Incorrect Array Lengths #

• Merge logic relies on three pointers (to traverse DTA, DTB, and big_array) and accurate length values for both input arrays. Common mistakes here include:
  • Using sizeof() on a passed array parameter (this only gives the size of the pointer, not the array itself—you need to track lengths separately when passing arrays to functions).
  • Letting your traversal pointers (i, j, k) go beyond the bounds of their respective arrays.
• A correct merge loop should look something like this (adjust based on your data types):

  int i = 0, j = 0, k = 0;
  int lenA = /* precomputed length of DTA */;
  int lenB = /* precomputed length of DTB */;
  
  // Merge elements in order until one array is exhausted
  while (i < lenA && j < lenB) {
      if (DTA[i] <= DTB[j]) {
          big_array[k++] = DTA[i++];
      } else {
          big_array[k++] = DTB[j++];
      }
  }
  
  // Add remaining elements from DTA
  while (i < lenA) {
      big_array[k++] = DTA[i++];
  }
  
  // Add remaining elements from DTB
  while (j < lenB) {
      big_array[k++] = DTB[j++];
  }
  

3. Uninitialized Variables in Merge Logic #

• If you forgot to initialize your traversal pointers (i, j, k) to 0, they'll hold random garbage values. Accessing arrays using these invalid indices will cause a crash. Always double-check that these variables start at 0 before your merge loop runs.

If you can share the full code for your merge step, we can pinpoint the exact line causing the crash. But start with these checks—they cover 90% of merge-related crashes after a working sort!

内容的提问来源于stack exchange，提问作者user214