BZOJ3850: ZCC Loves Codefires

题目：http://www.lydsy.com/JudgeOnline/problem.php?id=3850

题解：类似于国王游戏，推一下相邻两个元素交换的条件然后排个序就可以了。

代码：

 1 #include<cstdio>
 2 
 3 #include<cstdlib>
 4 
 5 #include<cmath>
 6 
 7 #include<cstring>
 8 
 9 #include<algorithm>
10 
11 #include<iostream>
12 
13 #include<vector>
14 
15 #include<map>
16 
17 #include<set>
18 
19 #include<queue>
20 
21 #include<string>
22 
23 #define inf 1000000000
24 
25 #define maxn 200000+5
26 
27 #define maxm 200000+5
28 
29 #define eps 1e-10
30 
31 #define ll long long
32 
33 #define pa pair<int,int>
34 
35 #define for0(i,n) for(int i=0;i<=(n);i++)
36 
37 #define for1(i,n) for(int i=1;i<=(n);i++)
38 
39 #define for2(i,x,y) for(int i=(x);i<=(y);i++)
40 
41 #define for3(i,x,y) for(int i=(x);i>=(y);i--)
42 
43 #define for4(i,x) for(int i=head[x],y=e[i].go;i;i=e[i].next,y=e[i].go)
44 
45 #define for5(n,m) for(int i=1;i<=n;i++)for(int j=1;j<=m;j++)
46 
47 #define mod 1000000007
48 
49 using namespace std;
50 
51 inline int read()
52 
53 {
54 
55     int x=0,f=1;char ch=getchar();
56 
57     while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();}
58 
59     while(ch>='0'&&ch<='9'){x=10*x+ch-'0';ch=getchar();}
60 
61     return x*f;
62 
63 }
64 struct rec{int x,y;}a[maxn];
65 int n;
66 inline bool cmp(rec a,rec b){return a.x*b.y<b.x*a.y;}
67 
68 int main()
69 
70 {
71 
72     freopen("input.txt","r",stdin);
73 
74     freopen("output.txt","w",stdout);
75 
76     n=read();
77     for1(i,n)a[i].x=read();
78     for1(i,n)a[i].y=read();
79     sort(a+1,a+n+1,cmp);
80     ll ans=0,sum=0;
81     for1(i,n)
82     {
83         sum+=a[i].x;
84         ans+=sum*(ll)a[i].y;
85     }
86     cout<<ans<<endl;
87 
88     return 0;
89 
90 }
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posted @ 2015-01-08 18:01  ZYF-ZYF  Views(158)  Comments(0)  Edit  收藏  举报