50. Pow(x, n)
實現 pow(x, n)，它計算 x 的 n 次方（即，x^n）。
範例 1：
輸入：x = 2.00000, n = 10 輸出：1024.00000
Python
class Solution:
def myPow(self, x: float, n: int) -> float:
if n == 0:
return 1
if n < 0:
x = 1 / x
n = -n
if n % 2 == 0:
half = self.myPow(x, n // 2)
return half * half
else:
return x * self.myPow(x, n - 1)
# Example usage:
sol = Solution()
print(sol.myPow(2.00000, 10)) # Output: 1024.00000
16.6MB, 33ms
C++
class Solution {
public:
double myPow(double x, int n) {
long long N = n; // Use a long long type to handle negative edge cases safely
if (N < 0) {
x = 1 / x;
N = -N;
}
return powHelper(x, N);
}
private:
double powHelper(double x, long long n) {
if (n == 0) {
return 1;
}
double half = powHelper(x, n / 2);
if (n % 2 == 0) {
return half * half;
} else {
return x * half * half;
}
}
};
// Example usage:
// Solution sol;
// cout << sol.myPow(2.00000, 10); // Output: 1024.00000
8.09MB, 0ms
Javascript
/**
* @param {number} x
* @param {number} n
* @return {number}
*/
var myPow = function(x, n) {
if (n === 0) {
return 1;
}
// Handle negative exponents
if (n < 0) {
x = 1 / x;
n = -n;
}
return powHelper(x, n);
};
function powHelper(x, n) {
if (n === 0) {
return 1;
}
const half = powHelper(x, Math.floor(n / 2));
if (n % 2 === 0) {
return half * half;
} else {
return x * half * half;
}
}
// Example usage:
console.log(myPow(2.00000, 10)); // Output: 1024.00000
console.log(myPow(2.00000, -2)); // Output: 0.25000
48.97MB, 57ms
