学步园

需要注意的一个细节是 s0 s1 s2改变后，不能再用 d[i][s1][s2] 来更新dp值。最好用引用来简化代码并减少出错。

Run Time: 0.549s

#define UVa  "LT9-15.10817.cpp"		//Headmaster's Headache
char fileIn[30] = UVa, fileOut[30] = UVa;

#include<cstring>
#include<cstdio>
#include<algorithm>
#include<vector>
#include<iostream>
#include<sstream>
#include<string>

using namespace std;

//Global Variables. Reset upon Each Case!
const int maxs = 8, maxm = 20 + 5, maxn = 100 + 5;
const int INF = 10000000;
int S, M, N;
int cost[maxm + maxn];
int subject[maxm + maxn];
int d[maxn+maxm][(1<<maxs)][1<<maxs];
/////


int dp(int i, int s0, int s1, int s2) {
    if(i >= N + M) {
        if(s0 != 0 || s1 != 0) return INF;
        return 0;
    }
    if(d[i][s1][s2] != -1) return d[i][s1][s2];

    int& ans = d[i][s1][s2] = INF;

    if(i >= M) ans = dp(i+1, s0, s1, s2);
    int t1 = s0 & subject[i];      //0 -> 1
    int t2 = s1 & subject[i];      //1 -> 2
    s0 = s0^t1;
    s1 = (s1^t2) | t1;
    s2 = s2 | t2;

    ans = min(ans, dp(i + 1, s0, s1, s2) + cost[i]);
    return ans;
}

int main() {
    while(cin>>S>>M>>N && S) {
        getchar();
        memset(subject, 0, sizeof(subject));
        memset(d, -1, sizeof(d));
        int a;
        for(int i = 0; i < M + N; i ++) {
            string line;
            getline(cin, line);
            stringstream ss(line);
            ss>>cost[i];
            while(ss>>a)
                subject[i] |= 1<<(a-1);         //subject number starting from 0.
        }
        cout<<dp(0, (1<<S)-1, 0, 0)<<endl;
    }
    return 0;
}