Implement the function double Power(double base, int exponent) to find the exponent power of base. Library functions must not be used, and large numbers need not be considered.
Example 1:
Input: 2.00000, 10
Output: 1024.00000
Example 2:
Input: 2.10000, 3
Output: 9.26100
Example 3:
Input: 2.00000, -2
Output: 0.25000
Explanation: 2-2 = 1/22 = 1/4 = 0.25
Example 1:
Input: 2.00000, 10
Output: 1024.00000
Example 2:
Input: 2.10000, 3
Output: 9.26100
Example 3:
Input: 2.00000, -2
Output: 0.25000
Explanation: 2-2 = 1/22 = 1/4 = 0.25
illustrate:
-100.0 < x < 100.0
n is a 32-bit signed integer whose value is in the range [−231, 231 − 1] .
class Solution:
def myPow(self, x: float, n: int) -> float:
if x == 0:
return 0
if n < 0:
n = -n
x = 1/x
res = 1
while n != 0:
if n & 1:
res *= x
x *= x
n >>= 1
return round(res, 5)
if __name__ == '__main__':
solution = Solution()
a = 2.0000
b = 10
reslut = solution.myPow(a, b)
print(reslut)
a = 2.1000
b = 3
reslut = solution.myPow(a, b)
print(reslut)
a = 2.0000
b = -2
reslut = solution.myPow(a, b)
print(reslut)
"""
运行结果：
1024.0
9.261
0.25
Process finished with exit code 0
"""