Submission

Score: 100

User: KHOPAN

Problemset: อนุกรม

Language: c

Time: 0.003 second

Submitted On: 2025-09-30 10:14:51

#include <stdio.h>
#include <stdint.h>

int main(const int argc, const char* const* const argv) {
	uint64_t index;

	if(!scanf("%llu", &index)) {
		return 1;
	}

	if(index < 3) {
		printf("%u\n", index ? 1 : 0);
		return 0;
	}

	index -= 2;
	uint64_t lastCurrent;
	uint64_t current = 1;
	uint64_t last = 1;

	while(index--) {
		lastCurrent = current;
		current += last;
		last = lastCurrent;
	}

	printf("%llu\n", current);
	return 0;
}