UVALive 3971 组装电脑

Posted 2020-08-03 cyd2014

https://icpcarchive.ecs.baylor.edu/index.php?option=com_onlinejudge&Itemid=8&page=show_problem&problem=1972

http://7xjob4.com1.z0.glb.clouddn.com/df5832a56667ea3317ca9166994f1eb6

 

题意：给电脑配件，价格和性能，求在指定总价内配件的最低性能最大。

思路：用二分方法，找出性能，使这个性能以上的配件能在指定价格内买到，最小值最大问题。

 

 1 #include <bits/stdc++.h>
 2 using namespace std;
 3 
 4 const int maxn=1000+5;
 5 
 6 int n,b,num;
 7 char typec[25],namec[25];
 8 int price,quality;
 9 int fp[maxn][maxn],fq[maxn][maxn],m[maxn];
10 
11 vector <string> tp;
12 void trans()
13 {
14     int i,j,l;
15     string s=typec;
16     l=tp.size();
17     for(i=0;i<l;i++)
18     {
19         if(tp[i]==s)
20         {
21             m[i+1]++;
22             fp[i+1][m[i+1]]=price;
23             fq[i+1][m[i+1]]=quality;
24             return;
25         }
26     }
27     tp.push_back(s);
28     m[l+1]++;
29     fp[l+1][m[l+1]]=price;
30     fq[l+1][m[l+1]]=quality;
31 }
32 
33 int check(int qu)
34 {
35     int i,j,sum=0;
36     for(i=1;i<=num;i++)
37     {
38         int mi=1000000005;
39         for(j=1;j<=m[i];j++)
40         {
41             if(fq[i][j]>=qu && fp[i][j]<mi)
42                 mi=fp[i][j];
43         }
44         if(mi==1000000005)
45             return 0;
46         sum+=mi;
47     }
48     if(sum<=b)
49         return 1;
50     else
51         return 0;
52 }
53 
54 int main()
55 {
56     int T;
57     int i,j;
58     scanf("%d",&T);
59     while(T--)
60     {
61         scanf("%d %d",&n,&b);
62 
63         memset(m,0,sizeof(m));
64         tp.clear();
65         for(i=1;i<=n;i++)
66         {
67             scanf("%s %s %d %d",typec,namec,&price,&quality);
68             trans();
69         }
70         num=tp.size();
71 
72         int l=0,r=1000000005;
73         while(l+1<r)
74         {
75             int mid=(l+r)/2;
76             if(check(mid))
77             {
78                 l=mid;
79             }
80             else
81             {
82                 r=mid;
83             }
84         }
85 
86         printf("%d\\n",l);
87     }
88     return 0;
89 }

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