C++博客-algorithm-文章分类-java

java-------- permutation

wZt — Sun, 31 May 2009 14:24:00 GMT

public class Permutation {
    static int n;
    static int[] a;

    static boolean ifok(int k, int i) {
        if (k < i) {
            for (int t = k; t < i; t++) {
                if (a[t] == a[i])
                    return false;
            }
        }
        return true;
    }

    static void search(int k) {
        if (k == n) {
            for (int i : a) {
                System.out.print(i + "　");
            }
            System.out.println();
            return;
        }
        for (int i = k; i < n; i++) {
            if (ifok(k, i)) {
                int tmp = a[k];
                a[k] = a[i];
                a[i] = tmp;
                search(k + 1);
                tmp = a[k];
                a[k] = a[i];
                a[i] = tmp;
            }
        }
    }

    public static void main(String[] args) {
        int a1[] = { 1, 1, 2, 2 };
        n = a1.length;
        a = a1;
        Arrays.sort(a);
        search(0);
    }
}

wZt 2009-05-31 22:24 发表评论

java FileWriter

wZt — Fri, 22 May 2009 16:54:00 GMT

    public static void main(String[] arg) throws IOException {
        FileWriter q = new FileWriter(
                new File("c:\\1.txt"));

        BufferedWriter k=new BufferedWriter(q);
        k.write("asdsad");
        k.close();
    }

wZt 2009-05-23 00:54 发表评论

java PirorityQueue

wZt — Tue, 19 May 2009 14:53:00 GMT

class data implements Comparable {
    int a;
    int b;
@Override
    public int compareTo(Object o) {
        return a - ((data) o).a;
    }
    public String toString(){
        return Integer.toString(this.a)+"::"+Integer.toString(this.b);
    }
}
public class test {
    public static void main(String[] args) {
        data[] temp = new data[10];
        PriorityQueue<data> q=new PriorityQueue<data>();
        for (int i = 0, j = 10; i < 10; i++, j--) {
            temp[i] = new data();
            temp[i].a = j;
            temp[i].b = i;
            q.add(temp[i]);
        }
        //Arrays.sort(temp);
        while(q.peek()!=null){
        System.out.println(q.remove()+" ");}
    }
}

wZt 2009-05-19 22:53 发表评论

StringTokenizer!!!!!

wZt — Sun, 17 May 2009 07:19:00 GMT

1        String a="1,2|3 4,5:6,7,8";
2        StringTokenizer test=new StringTokenizer(a," ,:|");
3        while(test.hasMoreTokens()){
4            System.out.print(test.nextToken());
5        }

wZt 2009-05-17 15:19 发表评论

java class sort

wZt — Tue, 12 May 2009 16:31:00 GMT

1//方法二===================================
2class data implements Comparable {
3    int a;
4    int b;
5
6    @Override
7    public int compareTo(Object o) {
8        return a - ((data) o).a;
9    }
10    public String toString(){
11        return Integer.toString(this.a)+","+Integer.toString(this.b);
12    }
13}
14public class test {
15    public static void main(String[] args) {
16        data[] temp = new data[10];
17        for (int i = 0, j = 10; i < 10; i++, j--) {
18            temp[i] = new data();
19            temp[i].a = j;
20            temp[i].b = i;
21        }
22        Arrays.sort(temp);
23        System.out.println(Arrays.asList(temp));
24    }
25}

1import java.math.*;
2import java.util.*;
3import java.io.*;
4//方法一===============================================================
5class data {
6    public int i;
7    public int j;
8
9}
10
11class cmp implements Comparator {
12    @Override
13    public int compare(Object o1, Object o2) {
14        return ((data) o1).i - ((data) o2).i;//从小到大
15        // return 0;
16    }
17}
18
19public class test {
20
21    public static void main(String[] arg) {
22
23        data[] a = new data[10];
24
25        for(int i=0,j=10;i<10;i++,j--){
26            a[i]=new data();//每次必须初始化
27            a[i].i=i;
28            a[i].j=j;
29        }
30
31        Arrays.sort(a,new cmp());
32
33        for(int i=0;i<10;i++){
34            System.out.print(a[i].i+" ");
35        }
36
37    }
38}
39

wZt 2009-05-13 00:31 发表评论

ReadFile

wZt — Mon, 11 May 2009 14:19:00 GMT

1    public static void main(String[] arg) throws IOException {
2        FileReader q = new FileReader(
3                "G:\\project\\java\\topcoder\\test\\src\\test.java");

4        BufferedReader k = new BufferedReader(q);

5        String s;
6        while ((s = k.readLine()) != null) {
7            System.out.println(s);

8        }
9    }

wZt 2009-05-11 22:19 发表评论