Reduce, the C Way

Implement folds over int arrays: ``c /* left fold: acc = fn(acc, arr[i]) for i in [0, n), starting from init */ int fold_i(const int *arr, size_t n, int init, int (*fn)(int acc, int v)); /* convenience: sum via fold_i */ int sum_i(const int *arr, size_t n); /* max via fold_i (n == 0 returns INT_MIN) */ int max_i(const int *arr, size_t n); `` The boilerplate provides fn_add, fn_max as fold functions.

Difficulty: intermediate