codeforces 632C （练习Java排序）

题目：http://codeforces.com/contest/632/problem/C
套了Petr的Java板子，来练习一下，没想到写个排序都那么费劲，，

• 1.在Comparator中重载比较函数
• 2.重写一个String类，重载比较函数

1.在Comparator中重载比较函数 代码：

import java.io.OutputStream;//输入输出流import java.io.IOException;import java.io.InputStream;import java.io.PrintWriter;import java.util.Arrays;import java.util.StringTokenizer;import java.io.IOException;import java.io.BufferedReader;import java.io.InputStreamReader;import java.io.InputStream;import java.util.Comparator;/** * Built using CHelper plug-in * Actual solution is at the top */public class Main {    public static void main(String[] args) {        InputStream inputStream = System.in;        OutputStream outputStream = System.out;        InputReader in = new InputReader(inputStream);        PrintWriter out = new PrintWriter(outputStream);        TaskA solver = new TaskA();        solver.solve(1, in, out);        out.close();    }    static class TaskA {        public void solve(int testNumber, InputReader in, PrintWriter out) {            int n = in.nextInt();            String [] str = new String[n];            for(int i = 0;i < n;i++)                str[i] = in.next();            Arrays.sort(str,new Comparator<String>(){                @Override                public int compare(String a, String b) {                    return (a+b).compareTo(b+a);                }            });            for(int i = 0;i < n;i++)                out.print(str[i]);            out.println();        }        private void fun(){        }    }    static class InputReader {        public BufferedReader reader;        public StringTokenizer tokenizer;        public InputReader(InputStream stream) {            reader = new BufferedReader(new InputStreamReader(stream), 32768);            tokenizer = null;        }        public String next() {            while (tokenizer == null || !tokenizer.hasMoreTokens()) {                try {                    tokenizer = new StringTokenizer(reader.readLine());                } catch (IOException e) {                    throw new RuntimeException(e);                }            }            return tokenizer.nextToken();        }        public int nextInt() {            return Integer.parseInt(next());        }    }}

1.在Comparator中重载比较函数

和上面类似的：

import java.io.OutputStream;//输入输出流import java.io.IOException;import java.io.InputStream;import java.io.PrintWriter;import java.util.Arrays;import java.util.StringTokenizer;import java.io.IOException;import java.io.BufferedReader;import java.io.InputStreamReader;import java.io.InputStream;import java.util.Comparator;/** * Built using CHelper plug-in * Actual solution is at the top */public class Main {    public static void main(String[] args) {        InputStream inputStream = System.in;        OutputStream outputStream = System.out;        InputReader in = new InputReader(inputStream);        PrintWriter out = new PrintWriter(outputStream);        TaskA solver = new TaskA();        solver.solve(1, in, out);        out.close();    }    static class TaskA {        public void solve(int testNumber, InputReader in, PrintWriter out) {            int n = in.nextInt();            String [] str = new String[n];            for(int i = 0;i < n;i++)                str[i] = in.next();            Comparator<String> cmp = new Comparator<String>(){                @Override                public int compare(String a, String b) {                    return (a+b).compareTo(b+a);                }            };            Arrays.sort(str,cmp);            for(int i = 0;i < n;i++)                out.print(str[i]);            out.println();        }        private void fun(){        }    }    static class InputReader {        public BufferedReader reader;        public StringTokenizer tokenizer;        public InputReader(InputStream stream) {            reader = new BufferedReader(new InputStreamReader(stream), 32768);            tokenizer = null;        }        public String next() {            while (tokenizer == null || !tokenizer.hasMoreTokens()) {                try {                    tokenizer = new StringTokenizer(reader.readLine());                } catch (IOException e) {                    throw new RuntimeException(e);                }            }            return tokenizer.nextToken();        }        public int nextInt() {            return Integer.parseInt(next());        }    }}

2.重写一个String类，重载比较函数：

import java.io.OutputStream;//输入输出流import java.io.IOException;import java.io.InputStream;import java.io.PrintWriter;import java.util.Arrays;import java.util.StringTokenizer;import java.io.IOException;import java.io.BufferedReader;import java.io.InputStreamReader;import java.io.InputStream;import java.util.Comparator;/** * Built using CHelper plug-in * Actual solution is at the top */public class Main {    public static void main(String[] args) {        InputStream inputStream = System.in;        OutputStream outputStream = System.out;        InputReader in = new InputReader(inputStream);        PrintWriter out = new PrintWriter(outputStream);        TaskA solver = new TaskA();        solver.solve(1, in, out);        out.close();    }    static class TaskA {        public void solve(int testNumber, InputReader in, PrintWriter out) {            int n = in.nextInt();            S[] str = new S[n];            for(int i = 0;i < n;i++)                str[i] = new S(in.next());            Arrays.sort(str,0,n);            for(int i = 0;i < n;i++)                System.out.print(str[i].s);            //out.println();        }        private void fun(){        }    }    static class S implements Comparable<S>{        String s;        S(String ss){            s = ss;        }        public int compareTo(S p) {            return (s+p.s).compareTo(p.s+s);        }    }    static class InputReader {        public BufferedReader reader;        public StringTokenizer tokenizer;        public InputReader(InputStream stream) {            reader = new BufferedReader(new InputStreamReader(stream), 32768);            tokenizer = null;        }        public String next() {            while (tokenizer == null || !tokenizer.hasMoreTokens()) {                try {                    tokenizer = new StringTokenizer(reader.readLine());                } catch (IOException e) {                    throw new RuntimeException(e);                }            }            return tokenizer.nextToken();        }        public int nextInt() {            return Integer.parseInt(next());        }    }}