FilesExpand file tree

 master

/

ValidPerfectSquare.java

Copy path

Blame

More file actions

Blame

More file actions

Latest commit

 

History

History

History

34 lines (31 loc) · 801 Bytes

 master

/

ValidPerfectSquare.java

Copy path

Top

File metadata and controls

• Code
• Blame

34 lines (31 loc) · 801 Bytes

Raw

Copy raw file

Download raw file

Open symbols panel

Edit and raw actions

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

32

33

34

public class ValidPerfectSquare {

public boolean isPerfectSquare(int num) {

int i = 1;

while (num > 0) {

num -= i;

i += 2;

}

return num == 0;

}

public boolean isPerfectSquare2(int num) {

int low = 1, high = num;

while (low <= high) {

long mid = (low + high) >>> 1;

if (mid * mid == num) {

return true;

} else if (mid * mid < num) {

low = (int) mid + 1;

} else {

high = (int) mid - 1;

}

}

return false;

}

public boolean isPerfectSquare3(int num) {

long x = num;

while (x * x > num) {

x = (x + num / x) >> 1;

}

return x * x == num;

}

}