[BZOJ八月赛]字符串大师

#include<iostream>
#include<cstdio>
#include<cstring>
using namespace std;
int s[100005];
int vis[100005];
int re,l;
int main()
{
	int n;
	scanf("%d",&n);
	for(int i=1;i<=n;i++)
	{
		scanf("%d",&s[i]);
	}
	s[0]=s[1];
	for(int i=1;i<=n;i++)
	{
		if(s[i]!=s[i-1])
		{
			re=s[i];
			if(i==s[i])
			{
				vis[i]=1;
				continue;
			}
			int tmp=i%re;
			if(tmp==0) vis[i]=vis[re];
			else vis[i]=vis[tmp];
			continue;
		}
		int tmp=i%s[i];
		if(tmp==0) vis[i]=vis[s[i]];
		else vis[i]=vis[tmp];
	}
	for(int i=1;i<=n;i++)
	{
		if(vis[i]==0) printf("a");
		else printf("b");
	}
	return 0;
}