Problem #
Source: PAT 1133{target="_blank"}
Description #
Given a singly linked list, you are supposed to rearrange its elements so that all the negative values appear before all of the non-negatives, and all the values in [0, K] appear before all those greater than K. The order of the elements inside each class must not be changed. For example, given the list being 18→7→-4→0→5→-6→10→11→-2 and K being 10, you must output -4→-6→-2→7→0→5→10→18→11.
Input Specification #
Each input file contains one test case. For each case, the first line contains the address of the first node, a positive which is the total number of nodes, and a positive . The address of a node is a 5-digit nonnegative integer, and NULL is represented by .
Then N lines follow, each describes a node in the format:
Address Data Next
where Address is the position of the node, Data is an integer in [], and Next is the position of the next node. It is guaranteed that the list is not empty.
Output Specification #
For each case, output in order (from beginning to the end of the list) the resulting linked list. Each node occupies a line, and is printed in the same format as in the input.
Sample Input #
00100 9 10
23333 10 27777
00000 0 99999
00100 18 12309
68237 -6 23333
33218 -4 00000
48652 -2 -1
99999 5 68237
27777 11 48652
12309 7 33218Sample Output #
33218 -4 68237
68237 -6 48652
48652 -2 12309
12309 7 00000
00000 0 99999
99999 5 23333
23333 10 00100
00100 18 27777
27777 11 -1Solution #
Code #
#include <iostream>
#include <string>
#include <vector>
#include <unordered_map>
using namespace std;
int n, k;
string first;
struct Node
{
string add, next;
int data;
};
int main()
{
std::ios::sync_with_stdio(false);
std::cin.tie(0);
cin >> first >> n >> k;
Node tmp;
unordered_map<string, Node> linklist;
vector<Node> out;
for (int i = 0; i < n; i++)
{
cin >> tmp.add >> tmp.data >> tmp.next;
linklist.insert(make_pair(tmp.add, tmp));
}
tmp = linklist.find(first)->second;
while (true)
{
if (tmp.data < 0)
out.push_back(tmp);
if (tmp.next == "-1")
break;
tmp = linklist.find(tmp.next)->second;
}
tmp = linklist.find(first)->second;
while (true)
{
if (tmp.data <= k && tmp.data >= 0)
out.push_back(tmp);
if (tmp.next == "-1")
break;
tmp = linklist.find(tmp.next)->second;
}
/* tmp = linklist.find(first)->second;
while (true)
{
if (tmp.data == k)
{
out.push_back(tmp);
break;
}
if (tmp.next == "-1")
break;
tmp = linklist.find(tmp.next)->second;
} */
tmp = linklist.find(first)->second;
while (true)
{
if (tmp.data > k)
out.push_back(tmp);
if (tmp.next == "-1")
break;
tmp = linklist.find(tmp.next)->second;
}
int len = out.size() - 1;
for (int i = 0; i < len; i++)
cout << out[i].add << " " << out[i].data << " " << out[i + 1].add << endl;
cout << out[len].add << " " << out[len].data << " -1" << endl;
return 0;
}
