mark candidate[n] as used
arr[j + 1] = arr[j]; // 元素后移
。Line官方版本下载对此有专业解读
（三）未经批准设置无线电广播电台、通信基站等无线电台（站）的，或者非法使用、占用无线电频率，从事违法活动的。，这一点在WPS官方版本下载中也有详细论述
He identified creating a hand as one of the three most difficult problems facing makers of humanoid robotics. The other two were creating an artificial intelligence that allowed the robot to comprehend the world, and making robots in large numbers.，更多细节参见Line官方版本下载