java - 大于 lg N 的最小整数

Question

我在某处读到:

The smallest integer larger than lg N is the number of bits required to represent N in binary, in the same way that the smallest integer larger than log10 N is the number of digits required to represent N in decimal.

The Java statement

for (lgN = 0; N > 0; lgN++, N /= 2) ; 

is a simple way to compute the smallest integer larger than lg N

我可能在这里遗漏了一些东西，但是 Java 语句如何计算大于 lg N 的最小整数？

Answer 1

如果改写成while循环可能会更清楚:

lgN = 0
while( N > 0 ) {
    lgN++;
    N = N/2;
}

这可以被认为是“在我们移掉所有 1 之前我们必须右移多少次”(留下一个零)