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$ curl repovive.com/roadmaps/math-fundamentals/exponents-roots/perfect-square-implementation

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$ curl repovive.com/roadmaps/math-fundamentals/exponents-roots/perfect-square-implementation

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Perfect Square - Implementation - Exponents & Roots | Math Fundamentals | Repovive

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Math Fundamentals18 sections · 842 units13h total

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Perfect Square - Implementation

Binary search solution

Here's the binary search approach:


function isPerfectSquare(num)
    if num = 1 then
        return true
    left := 1
    right := num
    while left ≤ right
        mid := left + (right - left) / 2
        square := mid * mid
        if square = num then
            return true
        else if square < num then
            left := mid + 1
        else
            right := mid - 1
    return false

Time: $O(\log num)$ . Space: $O(1)$ . You avoid overflow by using $mid = left + (right - left) / 2$ instead of $(left + right) / 2$ .