我已将字典加载到树结构中,并成功获得了peller.c,并使用以下 load() 和 check() 实现进行编译。
但是,当我运行该程序时,我的 check() 函数将不正确的单词数计为拼写错误。 (对于 lalaland.txt,它是 17756 个单词中的 17187 个)。
我无法弄清楚我的代码出了什么问题,并且非常感谢任何可以帮助我指出正确方向的人。
typedef struct node
{
bool isword;
struct node *children[27];
}
node;
node *root = NULL;
// Function returns the position of any given letter in the alphabet e.g. a = 1, b = 2 etc. Returns 0 for an apostrophe.
int index(char letter)
{
if (isalpha(letter))
{
int i = letter - 96;
return i;
}
return 0;
}
// Keeps track of number of words loaded into dictionary.
unsigned int wordno = 0;
// Returns true if word is in dictionary else false
bool check(const char *word)
{
char newword[LENGTH + 1];
node *temp = root;
for (int j = 0; j < strlen(word); j++)
{
//Makes each letter of the input lowercase and inserts it into a new array.
newword[j] = tolower(word[j]);
}
for (int i = 0; i < strlen(word); i++)
{
//Finds the position of the character in the alphabet by making a call to index().
int letter = index(newword[i]);
if (temp->children[letter] == NULL)
{
return false;
}
else
{
temp = temp->children[letter];
}
}
if (temp->isword == true)
{
return true;
}
return false;
}
// Loads dictionary into memory, returning true if successful else false
bool load(const char *dictionary)
{
FILE *dict = fopen(dictionary, "r");
root = calloc(1, sizeof(node));
node *temp = root;
if (dict == NULL)
{
fprintf(stderr, "Could not load dictionary.\n");
return false;
}
char word[LENGTH+1];
while (fscanf(dict, "%s", word) != EOF)
{
for (int i = 0; i < strlen(word); i++)
{
int letter = index(word[i]);
if (temp->children[letter] == NULL)
{
temp->children[letter] = calloc(1, sizeof(node));
if ((temp->children[letter]) == NULL)
{
unload();
return false;
}
}
temp = temp->children[letter];
}
temp->isword = true;
wordno++;
}
return true;
}
最佳答案
node *temp = root;
应该放置在这个 while 循环内:
while (fscanf(dict, "%s", word) != EOF)
通过这样做,每次循环开始迭代文件中的新单词时,您都可以让 temp 返回并指向根节点。
关于CS50 Pset5 check() 将太多单词视为拼写错误,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/51664890/