c - 合并排序 C 中的字符串数组

Question

我正在尝试对从标准输入输入的字符串数组实现合并排序，但我不知道哪里出了问题。现在我正面临段错误。我应该如何修改我的代码？

main() {
    char temp;
    int i = 0;
    char Strings[NUM][LEN];

    printf("Please enter %d strings, one per line:\n", NUM);
    for (i; i < 25; i++) {
        fgets(&Strings[i][0], LEN, stdin);
    }

    i = 0;
    puts("\nHere are the strings in the order you entered:");
    for (i; i < 25; i++) {
        printf("%s\n", Strings[i]);
    }

    mergesort(Strings, NUM);

    i = 0;
    puts("\nHere are the strings in alphabetical order");
    for (i; i < 25; i++) {
        printf("%s\n", Strings[i]);
    }
}

int mergesort(char list[NUM][LEN], int length) { // First part
    mergesort_r(0, length, list);
    return 0;
}

int mergesort_r(int left, int right, char list[NUM][LEN]) { // Overloaded portion
    if (right - left <= 1) {
        return 0;
    }

    int left_start  = left;
    int left_end    = (left + right) / 2;
    int right_start = left_end;
    int right_end   = right;

    mergesort_r( left_start, left_end, list);
    mergesort_r( right_start, right_end, list);

    merge(list, left_start, left_end, right_start, right_end);
}

int merge(char list[NUM][LEN], int left_start, int left_end, int right_start, int right_end) {

    int left_length = left_end - left_start;
    int right_length = right_end - right_start;

    char *left_half[left_length];
    char *right_half[right_length];

    int r = 0;
    int l = 0;
    int i = 0;

    for (i = left_start; i < left_end; i++, l++) {
        strcpy(left_half[l], list[i]);
    }

    for (i = right_start; i < right_end; i++, r++) {
        strcpy(right_half[r], list[i]);
    }

    for (i = left_start, r = 0, l = 0; l < left_length && r < right_length; i++) {
        if (strcmp(left_half[l], right_half[r]) < 0) {
            strcpy(list[i], left_half[l++]);
        } else {
            strcpy(list[i], right_half[r++]);
        }
    }

    for ( ; l < left_length; i++, l++) {
        strcpy(list[i], left_half[l]);
    }
    for ( ; r < right_length; i++, r++) {
        strcpy(list[i], right_half[r]);
    }
    return 0;
}

我不确定是不是我传递的数组不正确，或者我什至没有正确执行交换。我对此束手无策，可以使用一些建议。

Answer 1

应该是

char left_half[left_length][LEN];
char right_half[right_length][LEN];