#include <stdio.h>
int fib(int n){
int fn_p_p = 0, fn_p = 1, fn, i;
for( i = 2; i <= n; i++ ) {
fn = fn_p_p+fn_p;
fn_p_p = fn_p;
fn_p = fn;
}
return fn;
}
int main(void) {
int n;
printf("fib(%d)=%d\n", n
, fib
(n
)); return 0;
}
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