Submission

Score: 100

User: SonnyHappy108

Problemset: อนุกรม

Language: cpp

Time: 0.003 second

Submitted On: 2026-04-14 12:37:23

#include <bits/stdc++.h>
using namespace std;

string addstring(string a, string b) {
    string s = "";
    int i = a.size() - 1;
    int j = b.size() - 1;
    int c = 0;
    while (i >= 0 || j >= 0 || c) {
        int n = c;
        if (i >= 0) n += a[i--] - '0';
        if (j >= 0) n += b[j--] - '0';
        s += (n % 10) + '0';
        c = n / 10;
    }

    reverse(s.begin(), s.end());
    return s;
}
int main(){
	string a="1",b="1";
	int n;
	cin >> n;
	for(int i=0;i<(n-1)/2;i++){
	    a=addstring(a,b);
	    b=addstring(a,b);
	}
	if(n%2==1){
	    cout << a;
	}
	else{
	    cout << b;
	}
}