CH Round #58 - OrzCC杯noip模拟赛day2

A:颜色问题

题目：http://ch.ezoj.tk/contest/CH%20Round%20%2358%20-%20OrzCC杯noip模拟赛day2/颜色问题

题解：算一下每个仆人到它的目的地的时间取max即可

代码：

 1 #include<cstdio>
 2 #include<cstdlib>
 3 #include<cmath>
 4 #include<cstring>
 5 #include<algorithm>
 6 #include<iostream>
 7 #include<vector>
 8 #include<map>
 9 #include<set>
10 #include<queue>
11 #include<string>
12 #define inf 1000000000
13 #define maxn 1500000
14 #define maxm 500+100
15 #define eps 1e-10
16 #define ll long long
17 #define pa pair<int,int>
18 #define for0(i,n) for(int i=0;i<=(n);i++)
19 #define for1(i,n) for(int i=1;i<=(n);i++)
20 #define for2(i,x,y) for(int i=(x);i<=(y);i++)
21 #define for3(i,x,y) for(int i=(x);i>=(y);i--)
22 #define mod 1000000007
23 using namespace std;
24 inline int read()
25 {
26     int x=0,f=1;char ch=getchar();
27     while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();}
28     while(ch>='0'&&ch<='9'){x=10*x+ch-'0';ch=getchar();}
29     return x*f;
30 }
31 int n,f[maxn],head[maxn];
32 struct edge{int go,next;}e[maxn];
33 int main()
34 {
35     freopen("input.txt","r",stdin);
36     freopen("output.txt","w",stdout);
37     n=read();
38     for1(i,n)
39     {
40         int x=read();
41         e[i].go=i;e[i].next=head[x];head[x]=i;
42         f[i]=inf;
43     }
44     for1(i,n)
45     {
46         int x=read();
47         for(int j=head[x];j;j=e[j].next)
48          {
49              int y=e[j].go;
50              if(y>=i)f[y]=min(f[y],y-i+1);else f[y]=min(f[y],n-i+y+1);
51          }
52     }
53     int ans=1;
54     for1(i,n)ans=max(ans,f[e[i].go]);
55     printf("%d\n",ans==inf?-1:ans);
56     return 0;
57 }

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