Java中数组的逆向排列

Python中的快速脏示例:

def permute(a, perm):
    result = []
    for x in perm:
        result.append(a[x - 1])
    return result

def invPermute(a, perm):
    result = [None] * len(perm) # Build a result list of correct length
    for i, x in enumerate(a):
        result[perm[i] - 1] = x
    return result

测试方法:

>>> perm = [2,3,4,1]
>>> invPermute(permute("ABCD", perm), perm)
['A', 'B', 'C', 'D']

你的意思是

ShuffledA[i] = a[perm[i]-1]

 inverseperm[perm[i]-1] = i + 1

它构建了

 inversePerm[4 1 2 3]

然后将现有的算法应用于[bc-da],得到原始的[ab-cd]

for (int i=0; i<a.length; i++) {
  String val = a[perm[i]-1];
}

Collections.shuffle(Arrays.asList(theArray));