rt

洛谷AC

求怎么死的

#include<bits/stdc++.h>
using namespace std;
int n;
string str;
int q[2000010],f[2000010];
int last[210][2000010],tot[210];
long long ans=0;
int main()
{
	freopen("game.in","r",stdin);
	freopen("game.out","w",stdout);
	cin>>n>>str;
	for(int i=0;i<n;i++)
	{
		int now=(int){str[i]};
		q[i]=-1;
		if(tot[now]==0)
		{
			last[now][0]=i;
			tot[now]=1;
			continue;
		}
		if(tot[now]!=0)
		{
			if(last[now][tot[now]-1]==i-1)
			{
				q[i]=i-1;
				last[now][tot[now]]=i;
				tot[now]++;
				continue;
			}
			int k=q[i-1],tar=last[now][tot[now]-1],j=1;
			while(j<=tot[now])
			{
				while(k>tar+1)
				{
					k=q[k-1];
				}
				if(k==-1)
				{
					q[i]=-1;
				    break;
				}
				if(k==tar+1)
				{
					q[i]=tar;
					break;
				}
				else
				{
					j+=2;
					tar=last[now][tot[now]-j];
				}
			}
			last[now][tot[now]++]=i;
		}
	}
	//for(int i=0;i<n;i++)cout<<q[i]<<" ";
	for(int i=0;i<n;i++)
	{
		if(q[i]!=-1)f[i]=f[q[i]-1]+1;
		//cout<<f[i]<<endl;
		ans+=f[i];
	}
	cout<<ans<<endl;
	fclose(stdin);
	fclose(stdout);
	return 0;
}