标签：ret contains poj for org main 解释权 http rmq
本文版权归ljh2000和博客园共有，欢迎转载，但须保留此声明，并给出原文链接，谢谢合作。
本文作者：ljh2000
作者博客：http://www.cnblogs.com/ljh2000-jump/
转载请注明出处，侵权必究，保留最终解释权！
Description
For the daily milking, Farmer John‘s N cows (1 ≤ N ≤ 50,000) always line up in the same order. One day Farmer John decides to organize a game of Ultimate Frisbee with some of the cows. To keep things simple, he will take a contiguous range of cows from the milking lineup to play the game. However, for all the cows to have fun they should not differ too much in height.
Farmer John has made a list of Q (1 ≤ Q ≤ 200,000) potential groups of cows and their heights (1 ≤ height ≤ 1,000,000). For each group, he wants your help to determine the difference in height between the shortest and the tallest cow in the group.
Input
Output
Sample Input
6 3
1
7
3
4
2
5
1 5
4 6
2 2
Sample Output
6 3 0
正解：ST表维护RMQ查询
解题报告：
RMQ裸题，ST表维护即可。
//It is made by ljh2000
#include <iostream>
#include <cstdlib>
#include <cstring>
#include <cstdio>
#include <cmath>
#include <algorithm>
using namespace std;
typedef long long LL;
const int MAXN = 50011;
int n,m,a[MAXN],f[MAXN][17],g[MAXN][17],belong[MAXN];
inline int getint(){
int w=0,q=0; char c=getchar(); while((c<‘0‘||c>‘9‘) && c!=‘-‘) c=getchar();
if(c==‘-‘) q=1,c=getchar(); while (c>=‘0‘&&c<=‘9‘) w=w*10+c-‘0‘,c=getchar(); return q?-w:w;
}
inline int querymax(int l,int r){
int t=belong[r-l+1];
return max(g[l][t],g[r-(1<<t)+1][t]);
}
inline int querymin(int l,int r){
int t=belong[r-l+1];
return min(f[l][t],f[r-(1<<t)+1][t]);
}
inline void work(){
n=getint(); m=getint(); for(int i=1;i<=n;i++) a[i]=getint(),f[i][0]=a[i],g[i][0]=a[i];
belong[1]=0; for(int i=2;i<=n;i++) belong[i]=belong[i>>1]+1;
for(int j=1;j<=16;j++)
for(int i=1;i<=n;i++) {
f[i][j]=f[i][j-1];
if(i+(1<<(j-1))<=n) f[i][j]=min(f[i][j],f[i+(1<<(j-1))][j-1]);
}
for(int j=1;j<=16;j++)
for(int i=1;i<=n;i++) {
g[i][j]=g[i][j-1];
if(i+(1<<(j-1))<=n) g[i][j]=max(g[i][j],g[i+(1<<(j-1))][j-1]);
}
int l,r;
while(m--) {
l=getint(); r=getint();
printf("%d\n",querymax(l,r)-querymin(l,r));
}
}
int main()
{
work();
return 0;
}
标签：ret contains poj for org main 解释权 http rmq
原文地址：http://www.cnblogs.com/ljh2000-jump/p/6279193.html
