g0301_0400.s0367_valid_perfect_square.Solution.kt Maven / Gradle / Ivy
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Kotlin-based LeetCode algorithm problem solutions, regularly updated
package g0301_0400.s0367_valid_perfect_square
// #Easy #Math #Binary_Search #Binary_Search_I_Day_3
// #2022_11_19_Time_137_ms_(94.55%)_Space_32.8_MB_(87.27%)
class Solution {
fun isPerfectSquare(num: Int): Boolean {
if (num == 0) {
// If num is 0 return false
return false
}
// long datatype can holds huge number.
var start: Long = 0
var end = num.toLong()
var mid: Long
while (start <= end) {
// until start is lesser or equal to end do this
// Finding middle value
mid = start + (end - start) / 2
if (mid * mid == num.toLong()) {
// if mid*mid == num return true
return true
} else if (mid * mid < num) {
// if num is greater than mid*mid then make start = mid + 1
start = mid + 1
} else if (mid * mid > num) {
// if num is lesser than mid*mid then make end = mid - 1
end = mid - 1
}
}
return false
}
}