Monistus

input/code.cpp: In function 'node* create_list(std::string)':
input/code.cpp:21:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   21 |   for (int i = 1; i < text.size(); i++) {
      |                   ~~^~~~~~~~~~~~~

#include <iostream>
#include <string>
#include <ctype.h>

struct node {
  char value;
  node* next;
};

node* add_node(char value) {
  node* newnode = new node;
  newnode->value = value;
  newnode->next = nullptr;
  return newnode;
}

node* create_list(std::string text) {
  node* head = add_node(text[0]);
  node* cur = head;
 
  for (int i = 1; i < text.size(); i++) {
    cur->next = add_node(text[i]);
    cur = cur->next;
  }
  return head;
}

void insert(node* head) {
  int len = head->value - '0';
  head->value = head->next->value;
  node* link_old = head->next;
  node* last = head;
  node* next_old = head->next->next;
  node* next_added; // bad names: next_added keeps newest that was added, next_old is on right side
  for (int i = 1; i < len; i++) {
    next_added = add_node(next_old->value);
    last->next = next_added;
    last = last->next;
    next_old = next_old->next;
  }
  last->next = link_old;
}

void print(node* head)
{
    node* cur = head;
    while (cur != nullptr) {
        std::cout << cur->value;
        cur = cur->next;
    }
}

int main() {
  std::string input;
  std::cin >> input;
  
  node* head = create_list(input);
  node* cur = head;
  node* last = head; // makes first num work
  while (cur->next != nullptr) { // misses [-1].value but that is never a number
    if (isdigit(cur->value)) {
      insert(cur);
      cur = last;
      continue;
    }
    last = cur;
    cur = cur->next;
  }

  print(head);

  return 0;
}

Test 1

Group: 1, 2

Verdict: ACCEPTED

Test 2

Group: 1, 2

Verdict: ACCEPTED

Test 3

Group: 1, 2

Verdict: ACCEPTED

Test 4

Group: 1, 2

Verdict: ACCEPTED

Test 5

Group: 1, 2

Verdict: ACCEPTED

Test 6

Group: 1, 2

Verdict: ACCEPTED

Test 7

Group: 1, 2

Verdict: ACCEPTED

Test 8

Group: 2

Verdict: ACCEPTED

Test 9

Group: 2

Verdict: ACCEPTED

Test 10

Group: 2

Verdict: ACCEPTED

Test 11

Group: 2

Verdict: ACCEPTED

Test 12

Group: 2

Verdict: ACCEPTED

Test 13

Group: 2

Verdict: ACCEPTED

Test 14

Group: 2

Verdict: ACCEPTED