the implementation of the Karatsuba algorithm, the method only counts the small numbers true, but the big answer is not correct, what's the problem?

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The implementation of the Karatsuba algorithm, the method only counts the small numbers true, but the big answer is not correct, what's the problem?

var x = "1685287499328328297814655639278583667919355849391453456921116729";
var y = "7114192848577754587969744626558571536728983167954552999895348492";

function karatsuba(x, y) {
    if (x.length < 2 && y.length < 2) {
        return BigInt(parseInt(x) * parseInt(y));
    }
    var m = Math.min(x.length, y.length);
    var m2 = m / 2;
    var a = BigInt(x.substring(0, m2));
    var b = BigInt(x.substring(m2));
    var c = BigInt(y.substring(0, m2));
    var d = BigInt(y.substring(m2));
    var ac = a * c;
    var bd = b * d;
    var sum = (a + b) * (c + d) - ac - bd;

    return BigInt(Math.pow(10, m)) * ac + BigInt(Math.pow(10, m2)) * sum + bd;
}

console.log(karatsuba(x, y));

karatsuba bigint algorithm javascript
3 Answers

Invoking Math.pow is very suspicious. According to documentation, it

Returns an implementation-dependent approximation to the result of raising x to the power y.

You don't want any approximations in Karatzuba.

user_34038340 
return BigInt(parseInt(x) * parseInt(y));

It defeats the point to multiply large things together before constructing a BigInt.

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