CODEWITHSUNDEEP
c++exponentiation
oglox
oglox

Reputation: 67

Exponential Algorithm with Addition

I'm trying to calculate the power of a number x^n, by just using pure addition like this: 2^4= 2+2+2+2+2+2+2+2 =16 so im using the following code to calculate 2^n:

add = x
for ( i = 1; i <= n-1; i++){
    add = add + add;
}
cout<< x << "^" << n << " = " << add << endl;

so if you want to calculate 3^4 you have to put add = add + add + add so my question is how do I make it work with any number that the user wants?

Upvotes: 1

Views: 742

Answers (2)

user1601259
user1601259

Reputation: 61

// first deal with pow = 1 or 0 cases not shown here
// pseudocode for pow >= 2
var = 0
for (i = 0; i < num^(pow - 2); i++)  // ^ is raising to power, not xor
    for (j = 0; j < num; j++) 
        var += num

As you can see with the "i" condition check you have to use the power function anyway so not really possible with pure addition

Upvotes: 0

Aidan Gomez
Aidan Gomez

Reputation: 8647

For base b to the x <=> b^x

in C and with STRICTLY addition

int sum = b;
int add = b;
for (int i = 0; i < n+(-1); ++i) {
    add = sum;
    for (int j = 0; j < b+(-1); ++j) {
        sum += add;
    }
}

Upvotes: 3

Related Questions