我在c中实现了一个可以从文件中读取的知识树。我的newStr函数有一个seg错误。我无法用这个问题测试我的其余代码。我对c没有太多的经验,如果能帮上忙,我将不胜感激。
我的.c文件
#包括
#包括
#包括“animal.h”
#包括
#包括
/*returns a new node for the given value*/
struct Node * newNode (char *newValue)
{
struct Node * tree;
tree = (struct Node*)malloc(sizeof(struct Node));
tree -> value = newStr(newValue);
return tree;
}
/* returns a new string with value passed as an argument*/
char * newStr (char * charBuffer)
{
int i;
int length = strlen(charBuffer);
char newStr;
if(charBuffer[0] == 'A' || charBuffer[0] == 'Q'){
for(i=1; i<length; i++)
newStr += charBuffer[i];
}
return (newStr + "\0");
}
/*Read from a File and create a tree*/
struct Node * readATree(FILE * f)
{
char c;
char buffer[100];
struct Node * newTree;
c = fgetc(f);
if (c == 'A'){
fgets(buffer, 100, f);
newTree = newNode(buffer);
newTree -> left = NULL;
newTree -> right = NULL;
}
else{
fgets(buffer, 100, f);
newTree = newNode(newStr(buffer));
newTree->left = readATree(f);
newTree->right = (struct Node *) readAtree(f);
}
return newTree;
}
/*Write Tree to a File*/
void writeAFile(struct Node* tree, FILE * f)
{
char buffer[100];
strcpy(buffer, tree->value);
if(tree != 0){
if(tree->left == NULL && tree->right == NULL){
fputc((char)"A", f);
fputs(buffer,f);
} else{
fputc((char)"Q",f);
fputs(buffer,f);
writeAFile(tree->left, f);
writeAFile(tree->right,f);
}
}
}
/*The play should start from here*/
int main (){
struct Node* node;
struct Node* root;
char ans[100];
char q[100];
FILE * f;
f = fopen("animal.txt", "r+");
if(f != NULL)
readATree(f);
else{
node = newNode("Does it meow?");
node->right = NULL;
node->right->right=NULL;
node->left->left=NULL;
node->left=newNode("Cat");
root = node;
}
while(node->left != NULL && node->right != NULL){
printf(node->value);
scanf(ans);
if(ans[0] == (char)"Y" || ans[0] == (char)"y")
node = node->left;
else if(ans[0] == (char)"N" || ans[0] == (char)"n")
node = node->right;
else
printf("That is not a valid input.\n");
}
if(ans[0] == (char)"Y" || ans[0] == (char)"y")
printf("I win!");
else if(ans[0] == (char)"N" || ans[0] == (char)"n"){
printf("What is your animal");
scanf(ans);
printf("Please enter a yes or no question that is true about %s?\n", ans);
scanf(q);
node->right = newNode(q);
node->right->left = newNode(ans);
node->right->right = NULL;
}
writeAFile(root,f);
fclose(f);
return 0;
}
.h文件
#包括
struct Node {
char *value;
struct Node * left;
struct Node * right;
};
struct Node * newNode (char *newValue) ;
char * newStr (char * charBuffer);
struct Node * readATree(FILE * f);
void writeAFile(struct Node* tree, FILE * f);
最佳答案
可能还有几个问题,但这里有一些问题:
你的newStr功能非常,
非常错误。我猜你会想要
类似于:
char * newStr (char * charBuffer)
{
char *newStr;
if(charBuffer[0] == 'A' || charBuffer[0] == 'Q') {
newStr = strdup(&charBuffer[1]);
} else {
newStr = strdup("");
}
if(newStr == NULL) {
//handle error
}
return newStr;
}
不能将字符串转换为char
就像你在这里一样:
if(ans[0] == (char)"Y" || ans[0] == (char)"y")
改为(类似代码相同
其他地方也一样)
if(ans[0] =='Y' || ans[0] == 'y')
和上面一样当你打电话给电脑的时候,
不要这样做
fputc((char)"A", f);
做
fputc('A', f);
scanf需要一个格式字符串,不要
做:
scanf(ans);
例如(或者再次使用fgets)
if(scanf("%99s",ans) != 1) {
//handle error
}
关于c - 知识树中的段故障,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/3366760/