题目描述：
找出1~n的数字中缺失的两个数
代码：
public class FindMissNumber {
public static int[] findMissNumber(int[] arr) {
if (null == arr || arr.length <= 1) {
return new int[]{-1, -1};
}
boolean[] b = new boolean[arr.length + 2];
int[] rets = new int[2];
for (int i = 0; i < arr.length; i++) {
b[arr[i] - 1] = true;
}
int j = 0;
for (int i = 0; i < b.length; i++) {
if (!b[i]) {
rets[j++] = i + 1;
}
}
return rets;
}
public static void main(String[] args) {
int[] arr = {2, 4, 3, 9, 5, 6, 1};
int[] missNumber = findMissNumber(arr);
for (int i = 0; i < missNumber.length; i++) {
System.out.println(missNumber[i]);
}
}
}
