1 package number;
2
3 /**
4 * @author ycsun E-mail:stevesun521@gmail.com
5 * @version 创建时间：2012-10-3 下午2:59:49 类说明
6 */
7 public class ArrayOperation {
8 private int[] arr;
9 private int[] aux;
10 private int groupid = 0;
11
12 public ArrayOperation(int[] arr) {
13 this.arr = arr;
14 aux = new int[arr.length];
15 }
16
17 /**
18 * @param int[] arr 一个整数组，长度为 n，将其分为 m 份，使各的和相等求 m 的最大值，比如{3,2,4,3,6}
19 * 可以分成{3,2,4,3,6,} m=1;{3,6}{2,4,3}m=2 {3,3}{2,4}{6} m=3 所以m的最大值是3
20 */
21 public int averageSplitArray() {
22 if (arr.length == 1) {
23 return 1;
24 }
25 int res = 1;
26 int sum = 0;
27 for (int i = 0; i < arr.length; i++)
28 sum += arr[i];
29 for (int i = 1; i < arr.length; i++) {
30 if (sum % i != 0)
31 continue;
32 groupid = 0;
33 for (int j = 0; j < arr.length; j++)
34 aux[j] = 0;
35 averageSplitArray(i,sum / i,sum/i);
36 int gnum = i;
37 if (gnum > 0) {
38 System.out.println("gnum :" + gnum);
39 for (int g = 1; g <= i; g++) {
40 System.out.print("{");
41 for (int k = 0; k < aux.length; k++) {
42 if (aux[k] == g) {
43 System.out.print(arr[k] + ",");
44 }
45 }
46 System.out.println("}");
47 }
48 }
49 }
50 return res;
51 }
52
53 private boolean averageSplitArray(int groupnum,int groupsum,int goalsum) {
54 if (goalsum == 0) {
55 groupid++;
56 goalsum=groupsum;
57 if (groupid == groupnum + 1)
58 return true;
59 }
60 for (int i = 0; i < aux.length; i++) {
61 if (aux[i] != 0)
62 continue;
63 aux[i] = groupid;
64 if(averageSplitArray(groupnum,groupsum,goalsum-arr[i])) return true;
65 aux[i]=0;
66 }
67 return false;
68 }
69
70 public static void main(String[] args) {
71 int[] arr = { 3, 2, 4, 3, 6 };
72 ArrayOperation ao = new ArrayOperation(arr);
73 ao.averageSplitArray();
74 }
75
76 }
