30 lines
390 B
C
30 lines
390 B
C
#include <stdio.h>
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unsigned long long int fibonacci(int n);
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int main (void){
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puts("Enter fibonacci step!");
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int n;
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if(!scanf("%d", &n)){
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puts("invalid");
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return 1;
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}
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printf("%d. step of fibonacci: %llu\n", n, fibonacci(n));
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return 0;
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}
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unsigned long long int fibonacci(int n) {
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if(n == 0 || 1 == n){
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return n;
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} else {
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return fibonacci(n - 1) + fibonacci (n - 2);
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}
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}
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