蓝桥杯--状态压缩DP

P1460 - [蓝桥杯2019初赛]糖果 - New Online Judge (ecustacm.cn)

题解参考：(9条消息) 蓝桥杯省赛[新手向题解] 2019 第十届 C/C++ A组 第九题 DP_weixin_33801856的博客-CSDN博客

#include <iostream>
#include <cstring>
#include <algorithm>
#include <cmath>

using namespace std;

const int N = 1 << 20;

int n, m, k;
int f[N], w[N];

int main()
{
    cin >> n >> m >> k;
    memset(f, 0x3f, sizeof f);//求最小值我们就初始化为最大值
    for(int i = 0; i < n; i ++ )
    {
        int st = 0;
        for(int j = 0; j < k; j ++ )
        {
            int x;  cin >> x;
            x = pow(2, x - 1);
            st |= x;//不可以直接或pow(2, x - 1)
            //st |= 1 << x;
        }
        w[i] = st;
        f[st] = 1;
    }
    for(int i = 0; i < n; i ++ )
    {
        int now = w[i];
        if(now == 0x3f3f3f3f)   continue;
        for(int j = 0; j < (1 << m); j ++ )
            f[now | j] = min(f[now | j], f[j] + 1);
    }
    
    int res = f[(1 << m) - 1];
    
    if(res == 0x3f3f3f3f)  res = -1;
    cout << res << endl;
    
    
    return 0;
}