Thread: bigint modpow

hello, im searching a function in c for modular exponentiation modpow using bigint.
i just find for c#, anyone can help?

By "bigint" you mean multiple precision arithmetic integer types?
Try libgmp.

i need this function

Code:

int power(int x, int exp, int n) 
{ 
    int res = 1;      // Initialize result 
  
    x = x % n;  // Update x if it is more than or  
                // equal to p 
  
    while (exp > 0) 
    { 
        // If y is odd, multiply x with result 
        if (exp & 1) 
            res = (res*x) % n; 
  
        // y must be even now 
        exp = exp>>1; // y = y/2 
        x = (x*x) % n;   
    } 
    return res; 
}

but whit type BIGINT instead int