Question

C++

Write a function that takes in as input a singly linked list that contains the digits to an integer in reverse order. For example: 0 → 0 → 1 = 100 or 3 → 2 → 1 = 123. Return the list as the number. You may assume there will be no leading zeros in the list. For example: 3 → 2 → 0. You may assume there will not be any negative integers.

Answer 1

#include <iostream>
using namespace std;

struct node {
    int data;
    node *next;
};

int to_number(node *list) {
    int number = 0;
    while (list != NULL) {
        number *= 10;
        number += list->data;
        list = list->next;
    }
    return number;
}

int main() {
    node *list = new node;
    list->data = 3;
    list->next = new node;
    list->next->data = 2;
    list->next->next = new node;
    list->next->next->data = 1;
    list->next->next->next = NULL;

    cout << to_number(list) << endl;
    return 0;
}