UVa #10817 Headmaster's Headache (例题9-15)

来源：互联网发布：vs2017 连接mysql 编辑：程序博客网时间：2024/06/07 06:50

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 Headachechar 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;}

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