Codeforces Gym 100543G Virus synthesis

从这里get的思路，膜拜一下

#pragma comment(linker, "/STACK:102400000,102400000")
#include<map>
#include<set>
#include<cmath>
#include<queue>
#include<stack>
#include<bitset>
#include<cstdio>
#include<string>
#include<cstring>
#include<algorithm>
#include<functional>
using namespace std;
typedef long long LL;
const int low(int x) { return x&-x; }
const int INF = 0x7FFFFFFF;
const int maxn = 2e5 + 10;
int T, ans, length;
char s[maxn];

struct Palindromic_Tree
{
	const static int maxn = 2e5 + 10;
	const static int size = 26;
	char s[maxn];
	int next[maxn][size], fail[maxn], len[maxn], half[maxn], dp[maxn];
	int ed, sz, last;
	void clear()
	{
		dp[2] = half[2] = last = fail[1] = fail[2] = 1;
		len[2] = (len[1] = -1) + 1;
		ed = 0;	sz = 3;
		for (int i = 0; i < size; i++)
		{
			next[1][i] = next[2][i] = 0;
		}
	}
	int Node(int length)
	{
		len[sz] = length;
		memset(next[sz], 0, sizeof(next[sz]));
		return sz++;
	}
	int get(int x)
	{
		while (s[ed] != s[ed - len[x] - 1]) x = fail[x];
		return x;
	}
	void add(char pos)
	{
		int x = (s[++ed] = pos) - 'A', y = get(last);
		if (!(last = next[y][x]))
		{
			last = next[y][x] = Node(len[y] + 2);
			fail[last] = len[last] == 1 ? 2 : next[get(fail[y])][x];
			if (!(len[last] & 1))
			{
				half[last] = half[y];
				for (int &i = half[last]; s[ed] != s[ed - len[i] - 1] || len[i] + 2 > len[last] / 2;)
				{
					i = fail[i];
					while ((len[i] >= 0) && (len[i] & 1)) i = fail[i];
				}
				half[last] = len[half[last]] < 0 ? 2 : next[half[last]][x];
				dp[last] = min(dp[y] + 1, len[last] / 2 - len[half[last]] + dp[half[last]] + 1);
				ans = min(ans, length - len[last] + dp[last]);
			}
		}
	}
}solve;


int main()
{
	scanf("%d", &T);
	while (T--)
	{
		solve.clear();
		scanf("%s", s);
		ans = length = strlen(s);
		for (int i = 0; i < length; i++) solve.add(s[i]);
		printf("%d\n", ans);
	}
	return 0;
}