hdu 4628 状态压缩dp

字符串最多只有16位直接暴力。

//hdu 4628 状态压缩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()读取空格，不然不知道自己死在哪里
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;
}