Codility 28번 MinPerimeterRectangle

MinPerimeterRectangle

 

An integer N is given, representing the area of some rectangle.

The area of a rectangle whose sides are of length A and B is A * B, and the perimeter is 2 * (A + B).

The goal is to find the minimal perimeter of any rectangle whose area equals N. The sides of this rectangle should be only integers.

For example, given integer N = 30, rectangles of area 30 are:

• (1, 30), with a perimeter of 62,
• (2, 15), with a perimeter of 34,
• (3, 10), with a perimeter of 26,
• (5, 6), with a perimeter of 22.

Write a function:

class Solution { public int solution(int N); }

that, given an integer N, returns the minimal perimeter of any rectangle whose area is exactly equal to N.

For example, given an integer N = 30, the function should return 22, as explained above.

Write an efficient algorithm for the following assumptions:

• N is an integer within the range [1..1,000,000,000].

 

import java.util.*;

class Solution {
    public int solution(int N) {
        int cnt = 0;
        int min = Integer.MAX_VALUE;
        int sq = (int)Math.sqrt(N);
        for(int i=1; i<=sq; i++){
            if(N%i == 0){
                if((i + (N/i)) * 2 < min){
                    min =(i + (N/i)) * 2;
                }
            }
        }
        
        return min;
    }
}

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