Uva 组装电脑 12124 - Assemble

主要运用二分法查找最优解

 #include<iostream>
 #include<string>
 #include<vector>
 #include<map>
 using namespace std;

 const int maxn=+;

 int T,n,b,cnt;

 map<string,int> id;
 int ID(string s)
 {
     if(!id.count(s)) id[s]=cnt++;
     return id[s];
 }

 struct Component
 {
     int price;
     int quality;
 };
 vector<Component> comp[maxn]; 

 bool ok(int q)
 {
     int sum=;
     for(int i=;i<cnt;i++)
     {
         int cheapest=b+,m=comp[i].size();
         for(int j=;j<m;j++)
             if(comp[i][j].quality>=q)
                 cheapest=min(cheapest,comp[i][j].price);
         if(cheapest==b+) return false;
         sum+=cheapest;
         if(sum>b) return false;
     }
     return true;
 }

 int main()
 {
     cin>>T;
     for(int k=;k<=T;k++)
     {
         cin>>n>>b;
         cnt=;
         for(int i=;i<n;i++) comp[i].clear();
         id.clear();
         int maxq=;
         for(int i=;i<n;i++)
         {
             string type,name;
             int p,q;
             cin>>type>>name>>p>>q;
             maxq=max(maxq,q);
             comp[ID(type)].push_back((Component){p,q});
         }
         int L=,R=maxq;
         while(L<R)
         {
             int M=(L+R+)/;
             if(ok(M)) L=M;else R=M-;
         }
         cout<<L<<endl;
     }
     return ;
 }