P1:输出棋盘
P2:两个字符串表示的数相加,返回和的String
考虑溢出问题:
return Long.toString(((long)Integer.valueOf(s1)+(long)Integer.valueOf(s2)));
return Long.toString(( Long.valueOf(s1)+Long.valueOf(s2)));
P3:输入上下界,输出sum&average
average = (double) sum/(double) (this.upperbound-this.lowerbound+1);
此处average为double类型,右边的sum&差为int
若不加(double)赋值为int转double类型(精度下降--删去小数点后)
P4:乘法表