hdu 4628 狀態壓縮dp

字符串最多隻有16位直接暴力。

//hdu 4628 狀態壓縮dp
#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
#include<cstdlib>
#include<istream>
#include<vector>
#include<math.h>
#include<algorithm>
#include<string.h>
#define mod 10000009
#define long long ll
using namespace std;
char s[25];
int dp[1 << 16 + 1],len,all;

int init(int a)
{
	int i;
	vector<int> v;
	v.clear();
	for (i = 0;i <=len;i++)
	{
		if (a&(1 << i))
			v.push_back(i);
	}
	int t = v.size();
	t--;
	for (i = 0;i <= t / 2;i++)
		if (s[v[i]] != s[v[t-i]])
			return v.size();
	return 1;
}

int main()
{
	//freopen("d:\\in.txt", "r", stdin);
	int T;
	scanf("%d", &T);
	getchar();                     //注意要先用getchar()讀取空格，不然不知道自己死在哪裏
	while (T--)
	{
	    gets(s);
		len = strlen(s);
		all=1<<len;
		all--;
		int s0, s1, s2;
		for (s0 = 1;s0 < (1 << len);s0++)
		{
			dp[s0]=init(s0);
			for (s1 = s0;;s1 = (s1 - 1)&s0)
			{

                                int u=s0^s1;if(u>s1) break;

				dp[s0] = min(dp[s0], dp[s1] + dp[s0^s1]);
			}
        }
		printf("%d\n", dp[all]);
    }
	return 0;
}