UVA - 11235 - Frequent values （RMQ）

UVA - 11235

Frequent values

Time Limit: 3000MS

Memory Limit: Unknown

64bit IO Format: %lld & %llu

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Description

2007/2008 ACM International Collegiate Programming Contest 
University of Ulm Local Contest

Problem F: Frequent values

You are given a sequence of n integers a₁ , a₂ , ... , a_n in non-decreasing order. In addition to that, you are given several queries consisting of indices i and j (1 ≤ i ≤ j ≤ n). For each query, determine the most frequent value among the integers a_i , ... , a_j.

Input Specification

The input consists of several test cases. Each test case starts with a line containing two integers n and q (1 ≤ n, q ≤ 100000). The next line contains n integers a₁ , ... , a_n (-100000 ≤ a_i ≤ 100000, for each i ∈ {1, ..., n}) separated by spaces. You can assume that for each i ∈ {1, ..., n-1}: a_i ≤ a_i+1. The following q lines contain one query each, consisting of two integers i and j (1 ≤ i ≤ j ≤ n), which indicate the boundary indices for the query.

The last test case is followed by a line containing a single 0.

Output Specification

For each query, print one line with one integer: The number of occurrences of the most frequent value within the given range.

Sample Input

10 3
-1 -1 1 1 1 1 3 10 10 10
2 3
1 10
5 10
0

Sample Output

1
4
3

---

A naive algorithm may not run in time!

Source

Root :: Competitive Programming: Increasing the Lower Bound of Programming Contests (Steven & Felix Halim) :: Chapter 2. Data Structures and Libraries :: Data Structures With Our-Own Libraries ::  Segment Tree
Root :: Competitive Programming 3: The New Lower Bound of Programming Contests (Steven & Felix Halim) :: Data Structures and Libraries :: Data Structures with Our-Own Libraries ::  Tree-related Data Structures
Root :: AOAPC I: Beginning Algorithm Contests -- Training Guide (Rujia Liu) :: Chapter 3. Data Structures :: Maintaining Interval Data ::  Examples
Root :: Competitive Programming 2: This increases the lower bound of Programming Contests. Again (Steven & Felix Halim) :: Data Structures and Libraries :: Data Structures with Our-Own Libraries ::  Tree-related Data Structures

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思路：搞了我半天才搞出来，也是够啦，最后才发现是数组下标从一开始，我这代码凑合着用吧，因为是非降序的，所以进行游程编码（RLE），再算出区间内的最大值就好了

AC代码：

#include 
#include 
#include 
using namespace std;

const int maxn = 100005;
int a[maxn];
int value[maxn], coun[maxn];
int num[maxn], le[maxn], ri[maxn];
int d[maxn][400];
int maxnum;//最大编号

void RMQ_init() {
	for(int i = 0; i < maxnum+1; i++) d[i][0] = coun[i];
	for(int j = 1; (1 << j) <= maxnum+1; j++)
		for(int i = 0; i + (1<