Given a positive integer num, write a function which returns True if num is a perfect square else False. Note: Do not use any built-in library function such as sqrt. Example 1: Input: 16 Returns: True
Example 2: Input: 14 Returns: False
class Solution {public: bool isPerfectSquare(int num) { int begin = 1; int end = num; while(begin <= end){ long int x = (begin + end ) / 2; if(x * x == num) return true; if(x * x < num) begin = x + 1; if(x * x > num) end = x - 1; } return false; }};新聞熱點
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