Pow(x, n)
这个注意负数的情况, 用二分做.
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public class Solution { public double myPow(double x, int n) { if(n == 0) return 1; if(n == 1) return x; boolean neg = false; if(n < 0){ neg = true; n = -n; } int k = n / 2; int l = n - k * 2; double t1 = myPow(x,k); double t2 = myPow(x,l); if(neg) return 1/(t1*t1*t2); else return t1*t1*t2; } } |