POJ3581:Sequence(后缀数组)
2015-06-08 20:39
405 查看
Description
Given a sequence, {A1, A2, ..., An} which is guaranteed A1 > A2, ..., An, you are to cut it into three sub-sequences and reverse them
separately to form a new one which is the smallest possible sequence in alphabet order.
The alphabet order is defined as follows: for two sequence {A1, A2, ..., An} and {B1, B2, ..., Bn}, we say {A1, A2,
..., An} is smaller than {B1, B2, ..., Bn} if and only if there exists such i ( 1 ≤ i ≤ n) so that we have Ai < Bi and Aj = Bj for
each j < i.
Input
The first line contains n. (n ≤ 200000)
The following n lines contain the sequence.
Output
output n lines which is the smallest possible sequence obtained.
Sample Input
Sample Output
Hint
{10, 1, 2, 3, 4} -> {10, 1 | 2 | 3, 4} -> {1, 10, 2, 4, 3}
题意:把数组分成3分,每一份都翻转,要求输出字典序最小的结果
思路:参照http://blog.163.com/just_gogo/blog/static/1914390652011823103842787/
第二次求之所以要复制一次我们可以这样理解
首先320505,单纯这个的话,后缀按字典序排,第一是05,第二是0505
但是复制了之后,是第一是0505320505,第二是05320505
可见复制一遍还是有必要的
Given a sequence, {A1, A2, ..., An} which is guaranteed A1 > A2, ..., An, you are to cut it into three sub-sequences and reverse them
separately to form a new one which is the smallest possible sequence in alphabet order.
The alphabet order is defined as follows: for two sequence {A1, A2, ..., An} and {B1, B2, ..., Bn}, we say {A1, A2,
..., An} is smaller than {B1, B2, ..., Bn} if and only if there exists such i ( 1 ≤ i ≤ n) so that we have Ai < Bi and Aj = Bj for
each j < i.
Input
The first line contains n. (n ≤ 200000)
The following n lines contain the sequence.
Output
output n lines which is the smallest possible sequence obtained.
Sample Input
5 10 1 2 3 4
Sample Output
1 10 2 4 3
Hint
{10, 1, 2, 3, 4} -> {10, 1 | 2 | 3, 4} -> {1, 10, 2, 4, 3}
题意:把数组分成3分,每一份都翻转,要求输出字典序最小的结果
思路:参照http://blog.163.com/just_gogo/blog/static/1914390652011823103842787/
第二次求之所以要复制一次我们可以这样理解
首先320505,单纯这个的话,后缀按字典序排,第一是05,第二是0505
但是复制了之后,是第一是0505320505,第二是05320505
可见复制一遍还是有必要的
#include <iostream> #include <stdio.h> #include <string.h> #include <stack> #include <queue> #include <map> #include <set> #include <vector> #include <math.h> #include <bitset> #include <algorithm> #include <climits> using namespace std; #define LS 2*i #define RS 2*i+1 #define UP(i,x,y) for(i=x;i<=y;i++) #define DOWN(i,x,y) for(i=x;i>=y;i--) #define MEM(a,x) memset(a,x,sizeof(a)) #define W(a) while(a) #define gcd(a,b) __gcd(a,b) #define LL long long #define N 2000005 #define MOD 1000000007 #define INF 0x3f3f3f3f #define EXP 1e-8 int wa ,wb ,wsf ,wv ,sa ; int rank ,height ,s ; //sa:字典序中排第i位的起始位置在str中第sa[i] //rank:就是str第i个位置的后缀是在字典序排第几 //height:字典序排i和i-1的后缀的最长公共前缀 int cmp(int *r,int a,int b,int k) { return r[a]==r[b]&&r[a+k]==r[b+k]; } void getsa(int *r,int *sa,int n,int m)//n要包含末尾添加的0 { int i,j,p,*x=wa,*y=wb,*t; for(i=0; i<m; i++) wsf[i]=0; for(i=0; i<n; i++) wsf[x[i]=r[i]]++; for(i=1; i<m; i++) wsf[i]+=wsf[i-1]; for(i=n-1; i>=0; i--) sa[--wsf[x[i]]]=i; p=1; j=1; for(; p<n; j*=2,m=p) { for(p=0,i=n-j; i<n; i++) y[p++]=i; for(i=0; i<n; i++) if(sa[i]>=j) y[p++]=sa[i]-j; for(i=0; i<n; i++) wv[i]=x[y[i]]; for(i=0; i<m; i++) wsf[i]=0; for(i=0; i<n; i++) wsf[wv[i]]++; for(i=1; i<m; i++) wsf[i]+=wsf[i-1]; for(i=n-1; i>=0; i--) sa[--wsf[wv[i]]]=y[i]; t=x; x=y; y=t; x[sa[0]]=0; for(p=1,i=1; i<n; i++) x[sa[i]]=cmp(y,sa[i-1],sa[i],j)? p-1:p++; } } struct node { int id,num; } a ; int cmp1(node a,node b) { if(a.num!=b.num) return a.num<b.num; return a.id<b.id; } int main() { int n,i,j,k,maxn; scanf("%d",&n); for(i = n-1; i>=0; i--) { scanf("%d",&a[i].num); a[i].id = i; } sort(a,a+n,cmp1); for(i = 0; i<n; i++) { if(i && a[i].num == a[i-1].num) { s[a[i].id] = s[a[i-1].id]; continue; } s[a[i].id] = i+1; } s = 0; getsa(s,sa,n+1,n+10); for(i = 1; i<=n&&sa[i]<=1; i++); int tem = sa[i]; for(i = tem; i<n; i++) printf("%d\n",a[s[i]-1].num); for(i = 0; i<tem; i++) s[i+tem] = s[i]; tem*=2; s[tem] = 0; getsa(s,sa,tem+1,n+10); int p; for(i = 1; i<tem&&(!sa[i]||sa[i]>=tem/2); i++) ; p = sa[i]; for(i = p; i<tem/2; i++) printf("%d\n",a[s[i]-1].num); for(i = 0; i<p; i++) printf("%d\n",a[s[i]-1].num); return 0; }
相关文章推荐
- 黑马程序员——Java基础---GUI(图形用户界面)
- 监视器 RUIGE瑞鸽高清监视器TL-S1700HD
- gpio_direction_output 和 gpio_set_value用法的区别
- 响应式web设计之CSS3 Media Queries
- UIView属性
- UVA - 10911 Forming Quiz Teams
- 对于GUI监听按钮里面去调另一个方法时的错误
- 7款Android开发者常用的Android UI组件
- UInavigationcontroller中栈的概念和模态视图的切换
- GuozhongCrawler系列教程 (2) CrawTaskBuilder详解
- UILabel实现文本自适应方法(ios7)
- 关于Tableview头部添加图片或者其他东西的时候
- iOS 在UILabel显示不同的字体和颜色(转)
- private static final long serialVersionUID
- Azure在Build大会北京站
- 错误3:this class is not key value coding-compliant for the key Mylabelss
- Android charsequence
- String StringBuffer StringBuilder之间的区别
- easyui datagrid
- 【Android UI】RadioGroup+Fragment实现底部菜单栏