白書2.2.3 Best Cow Line

#include <iostream>
#include <vector>
using namespace std;

int main()
{
	int n;
	scanf("%d", &n);
	string arr;
	cin >> arr;
	int l = 0, r = n - 1;
	while (l <= r){
		bool left = false;
		for (int i = 0; l + i <= r; ++i){
			if (arr[l + i] > arr[r - i]){
				left = false;
				break;
			}
			else if (arr[l + i] < arr[r - i]){
				left = true;
				break;
			}
		}
		if (left)putchar(arr[l++]);
		else putchar(arr[r--]);
	}
	putchar('\n');
	return 0;
}