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1025 反转链表

给定一个常数 K 以及一个单链表 L,请编写程序将 L 中每 K 个结点反转。例如:给定 L 为 1→2→3→4→5→6,K 为 3,则输出应该为 3→2→1→6→5→4;如果 K 为 4,则输出应该为 4→3→2→1→5→6,即最后不到 K 个元素不反转。

输入格式:

每个输入包含 1 个测试用例。每个测试用例第 1 行给出第 1 个结点的地址、结点总个数正整数 N (≤105)、以及正整数 K (≤N),即要求反转的子链结点的个数。结点的地址是 5 位非负整数,NULL 地址用 −1 表示。

接下来有 N 行,每行格式为:

Address Data Next
Address Data Next

其中 Address 是结点地址,Data 是该结点保存的整数数据,Next 是下一结点的地址。

输出格式:

对每个测试用例,顺序输出反转后的链表,其上每个结点占一行,格式与输入相同。

输入样例:

tex
00100 6 4
00000 4 99999
00100 1 12309
68237 6 -1
33218 3 00000
99999 5 68237
12309 2 33218
00100 6 4
00000 4 99999
00100 1 12309
68237 6 -1
33218 3 00000
99999 5 68237
12309 2 33218

输出样例:

tex
00000 4 33218
33218 3 12309
12309 2 00100
00100 1 99999
99999 5 68237
68237 6 -1
00000 4 33218
33218 3 12309
12309 2 00100
00100 1 99999
99999 5 68237
68237 6 -1

Solution:

WARNING

测试点 5 运行超时

DANGER

测试点 6 答案错误

java
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.StreamTokenizer;

public class Main {
    public static void main(String[] args) throws IOException {
        StreamTokenizer in = new StreamTokenizer(new BufferedReader(new InputStreamReader(System.in)));
        in.nextToken();
        int[] list = new int[100001];
        int[] data = new int[100001];
        int[] next = new int[100001];
        int first = (int) in.nval;
        in.nextToken();
        int n = (int) in.nval;
        in.nextToken();
        int k = (int) in.nval;
        for (int i = 0; i < n; i++) {
            in.nextToken();
            int address = (int) in.nval;
            in.nextToken();
            data[address] = (int) in.nval;
            in.nextToken();
            next[address] = (int) in.nval;
        }
        int sum = 0;
        while (first != -1) {
            list[sum++] = first;
            first = next[first];
        }
        for (int i = 0; i < (sum - sum % k); i += k) {
            int len = i + k;
            int cnt = 0;
            for (int j = i; j < (len - i) / 2 + i; j++) {
                list[j] = list[j] + list[len - 1 - cnt] - (list[len - 1 - cnt] = list[j]);
                cnt++;
            }
        }
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < n - 1; i++) {
            sb.append(String.format("%05d %d %05d\n", list[i], data[list[i]], list[i + 1]));
        }
        sb.append(String.format("%05d %d -1", list[n - 1], data[list[n - 1]]));
        System.out.print(sb);
    }
}
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.StreamTokenizer;

public class Main {
    public static void main(String[] args) throws IOException {
        StreamTokenizer in = new StreamTokenizer(new BufferedReader(new InputStreamReader(System.in)));
        in.nextToken();
        int[] list = new int[100001];
        int[] data = new int[100001];
        int[] next = new int[100001];
        int first = (int) in.nval;
        in.nextToken();
        int n = (int) in.nval;
        in.nextToken();
        int k = (int) in.nval;
        for (int i = 0; i < n; i++) {
            in.nextToken();
            int address = (int) in.nval;
            in.nextToken();
            data[address] = (int) in.nval;
            in.nextToken();
            next[address] = (int) in.nval;
        }
        int sum = 0;
        while (first != -1) {
            list[sum++] = first;
            first = next[first];
        }
        for (int i = 0; i < (sum - sum % k); i += k) {
            int len = i + k;
            int cnt = 0;
            for (int j = i; j < (len - i) / 2 + i; j++) {
                list[j] = list[j] + list[len - 1 - cnt] - (list[len - 1 - cnt] = list[j]);
                cnt++;
            }
        }
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < n - 1; i++) {
            sb.append(String.format("%05d %d %05d\n", list[i], data[list[i]], list[i + 1]));
        }
        sb.append(String.format("%05d %d -1", list[n - 1], data[list[n - 1]]));
        System.out.print(sb);
    }
}

Released under the MIT License.