RosettaCodeData/Task/Lah-numbers/C/lah-numbers.c
2023-07-01 13:44:08 -04:00

38 lines
850 B
C

#include <stdint.h>
#include <stdio.h>
uint64_t factorial(uint64_t n) {
uint64_t res = 1;
if (n == 0) return res;
while (n > 0) res *= n--;
return res;
}
uint64_t lah(uint64_t n, uint64_t k) {
if (k == 1) return factorial(n);
if (k == n) return 1;
if (k > n) return 0;
if (k < 1 || n < 1) return 0;
return (factorial(n) * factorial(n - 1)) / (factorial(k) * factorial(k - 1)) / factorial(n - k);
}
int main() {
int row, i;
printf("Unsigned Lah numbers: L(n, k):\n");
printf("n/k ");
for (i = 0; i < 13; i++) {
printf("%10d ", i);
}
printf("\n");
for (row = 0; row < 13; row++) {
printf("%-3d", row);
for (i = 0; i < row + 1; i++) {
uint64_t l = lah(row, i);
printf("%11lld", l);
}
printf("\n");
}
return 0;
}