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#ifndef RANDOM_WEIGHT_H
#define RANDOM_WEIGHT_H
/*
* Weighted choice.
*
* Weights are assumed to be non-negative, but are allowed to be zero.
* Returns NULL if nothing found, i.e., if all weights are zero.
*/
template <typename T>
T* random_choose_weighted(std::vector<std::pair<T, int> >& choices)
{
int total = 0;
for (unsigned int i = 0; i < choices.size(); i++)
total += choices[i].second;
int r = random2(total);
int sum = 0;
for (unsigned int i = 0; i < choices.size(); i++)
{
sum += choices[i].second;
if (sum > r)
return (&choices[i].first);
}
return (NULL);
}
#endif
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