Permute the elements of an array - EPI

Permute the elements of an array

PermutationArray1.java
static void applyPermutation1(int[] perm, int[] A) {
  for (int i = 0; i < A.length; ++i) {
    if (perm[i] >= 0) {
      int a = i;
      int temp = A[i];
      do {
        int nextA = perm[a];
        int nextTemp = A[nextA];
        A[nextA] = temp;
        // Mark a as visited by using the sign bit.
    perm[a] -= perm.length;
    a = nextA;
    temp = nextTemp;
  } while (a != i);
 }
 }

  // Restore perm back.
  int size = perm.length;
  for (int i = 0; i < perm.length; i++) {
    perm[i] += size;
  }
}
PermutationArray2.java
static void applyPermutation2(int[] perm, int[] A) {
  for (int i = 0; i < A.length; ++i) {
    // Traverse the cycle to see if i is the min element.
    boolean isMin = true;
    int j = perm[i];
    while (j != i) {
      if (j < i) {
        isMin = false;
        break;
      }
      j = perm[j];
    }

    if (isMin) {
      int a = i;
      int temp = A[i];
      do {
        int nextA = perm[a];
        int nextTemp = A[nextA];
        A[nextA] = temp;
        a = nextA;
        temp = nextTemp;
      } while (a != i);
    }
  }
}