Java循环遍历不定长数组链表
功能描述
一个链表中保存多个不同长度的数组, 根据一个索引值, 能取到对应的元素所在的数组下标
public static int[] calcIndexArr(final List<String[]> list, int index) {
int listSize;
if (list == null || (listSize = list.size()) == 0) {
return new int[0];
}
int max = 1;
for (int i = 0; i < list.size(); i++) {
max *= list.get(i).length;
}
while (index >= max) {
index -= max;
}
int[] indexArr = new int[list.size()];
for (int i = 0; i < listSize; i++) {
int b = 1;
for (int j = i + 1; j < listSize; j++) {
b *= list.get(j).length;
}
int a = index / b;
indexArr[i] = a;
index = index - a * b;
}
return indexArr;
}
测试方法:
public void testCalcIndexArr() {
List<String[]> list = new ArrayList<String[]>();
list.add(new String[2]);
list.add(new String[4]);
list.add(new String[1]);
for (int i = 0; i < 30; i++) {
int arr[] = RandName.calcIndexArr(list, i);
assertEquals(3, arr.length);
System.out.println(arr[0] + "," + arr[1] + "," + arr[2]);
}
}
测试结果
0,0,0
0,1,0
0,2,0
0,3,0
1,0,0
1,1,0
1,2,0
1,3,0
0,0,0
0,1,0
0,2,0
0,3,0
1,0,0
1,1,0
1,2,0
1,3,0
0,0,0
0,1,0
0,2,0
0,3,0
1,0,0
1,1,0
1,2,0
1,3,0
0,0,0
0,1,0
0,2,0
0,3,0
1,0,0
1,1,0
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