P2761 软件补丁问题

P2761 软件补丁问题

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二进制储存状态+spfa

#include<iostream>
#include<algorithm>
#include<queue>
using namespace std;
int b1[102],b2[102],f1[101],f2[102];
int cost[102];
char in[102];
queue<int>q;
bool inque[1048577];
int dis[1048577];
int main()
{
    cin.sync_with_stdio(false);
    int n,m;
    cin>>n>>m;
    if(n==0)
    {
        //printf("0");
        cout<<"0";
        return 0;
    }
    int base,len;
    for(int i=1;i<=m;i++)	
    {
        cin>>cost[i];
        base=1;
        cin>>in;
        for(int j=0;in[j]!='';j++)
        {
            switch(in[j])
            {
                case '+':b1[i]+=base;break;
                case '-':b2[i]+=base;break;
                case '0':break;
            }
            base*=2;
        }
        base=1;
        cin>>in;
        for(int j=0;in[j]!='';j++)
        {
            switch(in[j])
            {
                case '-':f1[i]+=base;break;
                case '+':f2[i]+=base;break;
                case '0':break;
            }
            base*=2;
        }		
    }
    base=1;
    int begin=0;
    for(int i=1;i<=n;i++)
    {
        begin+=base;
        base*=2;
    }
    for(int i=0;i<=begin;i++)
        dis[i]=0x7ffffff;
    q.push(begin);
    dis[begin]=0;
    inque[begin]=true;
    int pass,nxt;
    while(!q.empty())
    {
        pass=q.front();
        q.pop();
        inque[pass]=false;
        for(int i=1;i<=m;i++)
        {
            if((pass&b1[i])!=b1[i])
                continue;
            if((pass&b2[i])!=0)
                continue;
            int ha=pass&f1[i];
            nxt=pass-ha;
            nxt=nxt|f2[i];
            if(dis[nxt]<dis[pass]+cost[i])
                continue;
            dis[nxt]=dis[pass]+cost[i];
            q.push(nxt);
            if(!inque[nxt])
                inque[nxt]=true;
        }
    }
    //printf("%d",dis[0]);
    cout << (dis[0] ==0x7ffffff?0:dis[0])<<endl;
}