ST表 || RMQ问题 || BZOJ 1699: [Usaco2007 Jan]Balanced Lineup排队 || Luogu P2880 [USACO07JAN]平衡的阵容Balanced Lineup

时间:2023-03-08 23:13:26
ST表 || RMQ问题 || BZOJ 1699: [Usaco2007 Jan]Balanced Lineup排队 || Luogu P2880 [USACO07JAN]平衡的阵容Balanced Lineup

题面:P2880 [USACO07JAN]平衡的阵容Balanced Lineup

题解:

ST表板子

代码:

 #include<cstdio>
#include<cstring>
#include<iostream>
#define max(a,b) ((a)>(b)?(a):(b))
#define min(a,b) ((a)<(b)?(a):(b))
using namespace std;
const int maxn=,max_log=,maxlog=,inf=<<;
int Fmx[maxn][max_log],N,Q,Fmn[maxn][max_log],LOG[maxn],A,B;
int main(){
scanf("%d%d",&N,&Q);
for(int i=;i<=N;i++)
for(int j=;j<=maxlog;j++)
Fmn[i][j]=inf;
for(int i=;i<=N;i++){
scanf("%d",&Fmx[i][]);
Fmn[i][]=Fmx[i][];
}
LOG[]=-;
for(int i=;i<=N;i++)LOG[i]=LOG[i>>]+;
for(int j=;j<=maxlog;j++)//
for(int i=;i+(<<j)-<=N;i++){
Fmx[i][j]=max(Fmx[i][j-],Fmx[i+(<<(j-))][j-]);
Fmn[i][j]=min(Fmn[i][j-],Fmn[i+(<<(j-))][j-]);
}
while(Q--){
scanf("%d%d",&A,&B);
int x=LOG[B-A+],ans1,ans2;
ans1=max(Fmx[A][x],Fmx[B-(<<x)+][x]);
ans2=min(Fmn[A][x],Fmn[B-(<<x)+][x]);
printf("%d\n",ans1-ans2);
}
return ;
}

By:AlenaNuna