#include <stdio.h>
int combi(int n, int r){
if (r == 0)
return 1;
else if(n == r)
return 1;
else if (r == 1)
return n;
else
return combi(n - 1, r - 1) + combi(n - 1, r);
}
int main(void){
int n, r;
n = 4, r = 2;
printf("C(n=%d, r=%d) = %d\n", n
, r
, combi
(n
, r
)); return 0;
}
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