第一个算法题 public static char[] trans(char[] arr) { int l = 0; int r = arr.length - 1; int m = 0; while (m < r) { if (arr[m] == 'B') { arr[l++] = 'B'; } else if (arr[m] == 'C') { arr[r--] = 'C'; } m++; } for (int i = l; i <= r; i++) { arr[i] = 'A'; } return arr; }