UVA 12124 - Assemble 解题报告

http://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=24&page=show_problem&problem=3276

这题是求最大的最小值，常用的方法就是二分了，需要注意的是二分的边界，每次二分得到一个品质因子，再把品质因子大于或等于的每类配件最小的价格加起来。不断的二分，找到最终的品质因子。

#include <cstdio>
#include <algorithm>
#include <map>
#include <vector>
#include <string>
using namespace std;
struct PeiJian
{
    int price;
    int quality;
};
bool cmp(PeiJian a,PeiJian b){
    if(a.price!=b.price)
        return a.price<b.price;
    return a.quality>b.quality;
}
int main(){
    int i,j;
    int T;
    scanf("%d",&T);
    while(T--){
        int n,money;
        char str1[1000];
        char str2[1000];
        map<string,int> mmm;
    	vector<PeiJian> vvv[1005];
        string str;
        PeiJian temp;
        int price;
        scanf("%d%d",&n,&money);
        int k=0;
        int maxq=-200000000;
        int minq;
        for(i=0;i<n;i++){
            scanf("%s %s %d %d",str1,str2,&temp.price,&temp.quality);
            if(maxq<temp.quality)
                maxq=temp.quality;
            str=str1;
            if(mmm.count(str)){
                vvv[mmm[str]].push_back(temp);
            }
            else{
                vvv[k].push_back(temp);
                mmm[str]=k;
                k++;
            }
        }
        for(i=0;i<k;i++){
            sort(vvv[i].begin(),vvv[i].end(),cmp);
        }
        int mid;
        int type_ccc;
        minq=0;
        while(minq<maxq){
            int sum=0;
            type_ccc=0;
            mid=(minq+maxq)/2;
            for(i=0;i<k;i++){
                for(j=0;j<vvv[i].size();j++){
                    if(vvv[i][j].quality>=mid){
                        sum+=vvv[i][j].price;
                        type_ccc++;
                        break;
                    }
                }
            }
            if(type_ccc==k && sum<=money)
                minq=mid;
            else
                maxq=mid-1;
        }
        printf("%d\n",minq);
    }
    return 0;
}

/*
3
6 703
processor 3500_MHz 66 5
processor 4200_MHz 103 7
processor 5000_MHz 156 9
processor 6000_MHz 219 12
memory 1_GB 35 3
memory 2_GB 600 6
18 800
processor 3500_MHz 66 5
processor 4200_MHz 103 7
processor 5000_MHz 156 9
processor 6000_MHz 219 12
memory 1_GB 35 3
memory 2_GB 88 6
memory 4_GB 170 12
mainbord all_onboard 52 10
harddisk 250_GB 54 10
harddisk 500_FB 99 12
casing midi 36 10
monitor 17_inch 157 5
monitor 19_inch 175 7
monitor 20_inch 210 9
monitor 22_inch 293 12
mouse cordless_optical 18 12
mouse microsoft 30 9
keyboard office 4 10

*/