Pow(x,n) Problem
Description
LeetCode Problem 50.
Implement pow(x, n), which calculates x raised to the power n (i.e., x^n).
Example 1:
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Input: x = 2.00000, n = 10
Output: 1024.00000
Example 2:
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Input: x = 2.10000, n = 3
Output: 9.26100
Example 3:
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Input: x = 2.00000, n = -2
Output: 0.25000
Explanation: 2-2 = 1/22 = 1/4 = 0.25
Constraints:
- -100.0 < x < 100.0
- -2^31 <= n <= 2^31-1
- -10^4 <= x^n <= 10^4
Sample C++ Code
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class Solution {
public:
double myPow(double x, int n) {
if (n == 0)
return 1;
bool neg = (n < 0) ? true : false;
long long m = abs(n);
double ans = 1;
while (m > 0) {
if (m & 1)
ans *= x;
x *= x;
m = m >> 1;
}
if (neg)
return 1 / ans;
else
return ans;
}
};