cc150 2.5

addtwonumber

# include <iostream>
using namespace std;
typedef struct node{
  int data;
  node *next;
}node;
node * addtwonumber(node*l1,node*l2){
  if (l1==NULL) return l2;
  if (l2==NULL) return l1;
  node *res, *pre=NULL;
  int carry=0;
  while(l1 && l2){
    int value = l1->data+l2->data+carry;
    node *nd= new node();
    nd->data=value%10;
    carry=value/10;
    if(pre){
      pre->next=nd;
      pre=nd;
    }
    else{
      res=pre=nd;
    }
    l1=l1->next;
    l2=l2->next;
  }
  while (l1){
    int value=l1->data+carry;
    node *nd=new node();
    nd->data=value;
    pre->next=nd;
    pre=nd;
    carry= value/10;
    l1=l1->next;
  }
  while (l2){
    int value=l2->data+carry;
    node *nd=new node();
    nd->data=value%10;
    pre->next=nd;
    pre=nd;
    carry= value/10;
    l2=l2->next;
  }
  if (carry>0){
    int value =carry;
    node *nd=new node();
    nd->data=value%10;
    pre->next=nd;
    
  }
  return res;
}