Satoshi Nakamoto's C code from the Bitcoin whitepaper for determining an attacker on the network's probability of success

Bitcoin.cpp

#include "math.h"
#include "stdio.h"

double AttackerSuccessProbability(double q, int z)
{
 double p = 1.0 - q;
 double lambda = z * (q / p);
 double sum = 1.0;
 int i; 
 int k;
 for (k = 0; k <= z; k++)
 {
     double poisson = exp(-lambda);
     
     for (i = 1; i <= k; i++)
     poisson *= lambda / i;
     sum -= poisson * (1 - pow(q / p, z - k));
 }
 return sum;
}

int main()
{
double ans = AttackerSuccessProbability(0.1, 1);
printf("'%f'", ans);
}