26. （阅读程序写结果）

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

#define MAX 100
void solve(char first[], int spos_f, int epos_f, char mid[], int spos_m, int epos_m)
{
	int i, root_m;
	if(spos_f > epos_f)
		return;
	for(i = spos_m; i <= epos_m; i++)
		if(first[spos_f] == mid[i])
		{
			root_m = i;
			break;
		}
	solve(first, spos_f + 1, spos_f + (root_m - spos_m), mid, spos_m, root_m - 1);
	solve(first, spos_f + (root_m - spos_m) + 1, epos_f, mid, root_m + 1, epos_m);
	cout << first[spos_f];
}

int main()
{
	char first[MAX], mid[MAX];
	int len;
	cin >> len;
	cin >> first >> mid;
	solve(first, 0, len - 1, mid , 0, len - 1);	
	cout << endl;
	return 0;
}

输入： 7

ABDCEGF

BDAGECF

输出：{{ input(1) }}