Uva 组装电脑 12124

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=1000+5;

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=0;
    for(int i=0;i<cnt;i++)
    {
        int cheapest=b+1,m=comp[i].size();
        for(int j=0;j<m;j++)
            if(comp[i][j].quality>=q) 
                cheapest=min(cheapest,comp[i][j].price);
        if(cheapest==b+1) return false;
        sum+=cheapest;
        if(sum>b) return false;
    }
    return true;
}

int main()
{
    cin>>T;
    for(int k=1;k<=T;k++)
    {
        cin>>n>>b;
        cnt=0;
        for(int i=0;i<n;i++) comp[i].clear();
        id.clear();
        int maxq=0;
        for(int i=0;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=0,R=maxq;
        while(L<R)
        {
            int M=(L+R+1)/2;
            if(ok(M)) L=M;else R=M-1;
        }
        cout<<L<<endl;
    }
    return 0;
}