[BAEKJOON] 2139 이친수

#define _CRT_SECURE_NO_WARNINGS #include <iostream> #include <vector> using namespace std; int main() { vector<long long>cache(2, 0); long long num; cin>>num; cache[0] = 0; cache[1] = 1; long long temp0, temp1; for (int j = 1; j < num; j++) { temp0 = cache[0] + cache[1]; temp1 = cache[0]; cache[0] = temp0; cache[1] = temp1; } cout << cache[0] + cache[1]; return 0; }