c++ - 链表 C++ 的错误打印

Question

请你解释一下，为什么函数“print”在这段代码中无限打印一个相同的数字？

显然，链表构造正确，但在逐步调试时，它停留在“打印”功能上。

#include <iostream>
#include <cstdlib>
#include <ctime>

using namespace std;

struct num {
    int n;
    num* next;};

void add (num*&head, int size) {
    num*newnode = new num;
    for (int i = 0; i<size; i++) {
        newnode->n = rand()%100;
        newnode->next = head;
        head = newnode;}
}

void print (num*head) {
    num*temp = head;
    while (temp != 0) {
        cout << temp->n << endl;
        temp = temp ->next;}}

void del (num*&head) {
    num*temp = 0;
    while (head!=0){
        temp = head;
        head = head->next;
        delete temp;}}

int main () {
srand ((unsigned int)time(0));
num*head = 0;
add (head, 10);
print (head);
del (head);
cin.get();
cin.ignore();
}

Answer 1

问题出在添加功能上。您不是在创建新节点。而是修改同一个节点并将其指向自身。

这样改

    for (int i = 0; i<size; i++) {
        newnode = new num; //new node
        newnode->n = rand()%100;
        newnode->next = head;
        head = newnode;}