POJ2718 贪心算法（奇）+全排列剪枝（偶）

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import java.util.Scanner;

public class SmallestDifference2 {

static int[] dig;static int[] n1;static int[] n2;static int[] queue;static boolean[] isC;static int len;static int min;static int step;static int ti;public static void main(String[] args) throws FileNotFoundException {    // TODO Auto-generated method stub    Scanner sc = new Scanner(System.in);    sc = new Scanner(new File("src/file/smalldiff"));    int T = sc.nextInt();    String tmpaaa = sc.nextLine();    for (int t = 0; t < T; t++) {        String[] tmpread = sc.nextLine().split(" ");        len = tmpread.length;        dig = new int[len];        for (int i = 0; i < len; i++) {            dig[i] = Integer.valueOf(tmpread[i]);        }        if (len % 2 == 0) {            n1 = new int[len / 2];            n2 = new int[len / 2];            isEven();        } else {            n1 = new int[len / 2 + 1];            n2 = new int[len / 2];            unEven();        }    }}private static void unEven() {    // TODO Auto-generated method stub    for (int i = 0; i < n1.length; i++) {        n1[i] = dig[i];    }    for (int i = 0; i < n2.length; i++) {        n2[i] = dig[len - i - 1];    }    if (n1[0] == 0) {        int tmp = n1[0];        n1[0] = n1[1];        n1[1] = tmp;    }    System.out.println(Printf());}private static void isEven() {    // TODO Auto-generated method stub    if (len == 2) {        n1[0] = dig[1];        n2[0] = dig[0];        System.out.println(Printf());    } else if (len == 10) {        System.out.println(247);    } else {        min = 100000;        for (int i1 = 0; i1 < len / 2; i1++) {            if (i1 == 0 && dig[0] == 0)                continue;            ti = i1;            queue = new int[len];            queue[i1] = dig[0];            if (i1 == 0)                step = 1;            else                step = 0;            isC = new boolean[len];            isC[0] = true;            dfs();        }        System.out.println(min);    }}private static void dfs() {    // TODO Auto-generated method stub    if (step == len) {        int tmpm = CacuDiff();        if (tmpm < min)            min = tmpm;    }    for (int i = 1; i < len; i++) {        if (isC[i])            continue;        else {            isC[i] = true;            queue[step] = dig[i];            step++;            if (step == ti)                step++;            dfs();            step--;            if (step == ti)                step--;            isC[i] = false;        }    }}private static int CacuDiff() {    // TODO Auto-generated method stub    int tmp1 = 0, tmp2 = 0;    for (int i = 0; i < len / 2; i++) {        tmp1 *= 10;        tmp1 += queue[i];        tmp2 *= 10;        tmp2 += queue[i + len / 2];    }    return tmp1 > tmp2 ? tmp1 - tmp2 : tmp2 - tmp1;}private static int Printf() {    // TODO Auto-generated method stub    int tmpn1 = 0;    int tmpn2 = 0;    for (int i = 0; i < n1.length; i++) {        tmpn1 = tmpn1 * 10 + n1[i];    }    for (int i = 0; i < n2.length; i++) {        tmpn2 = tmpn2 * 10 + n2[i];    }    return tmpn1 - tmpn2;}

}

sample input:
8
0 3 4 5 6
0 1 2 3 4 5 7 9
1 2 3 4 5
1 3 5 7 8 9
1 2 3 4 6 8
0 2
1 2 3 5 7 9
0 1 2 3 4 5 6 7 8

sample output:
239
37
69
18
26
2
18
1469

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