Time Limit: 1 Sec
Memory Limit: 256 MB
题目连接
http://acm.hdu.edu.cn/showproblem.php?pid=5443
Description
In Land waterless, water is a very limited resource. People always fight for the biggest source of water. Given a sequence of water sources with a1,a2,a3,...,an representing the size of the water source. Given a set of queries each containing 2 integers l and r, please find out the biggest water source between al and ar.
Input
First you are given an integer T(T≤10) indicating the number of test cases. For each test case, there is a number n(0≤n≤1000) on a line representing the number of water sources. n integers follow, respectively a1,a2,a3,...,an, and each integer is in {1,...,106}. On the next line, there is a number q(0≤q≤1000) representing the number of queries. After that, there will be q lines with two integers l and r(1≤l≤r≤n) indicating the range of which you should find out the biggest water source.
#include <cstdio>
#include <cmath>
#include <cstring>
#include <ctime>
#include <iostream>
#include <algorithm>
#include <set>
#include <vector>
#include <sstream>
#include <queue>
#include <typeinfo>
#include <fstream>
#include <map>
#include <stack>
typedef long long ll;
using namespace std;
//freopen("D.in","r",stdin);
//freopen("D.out","w",stdout);
#define sspeed ios_base::sync_with_stdio(0);cin.tie(0)
#define test freopen("test.txt","r",stdin)
#define maxn 10505
#define mod 10007
#define eps 1e-9
const int inf=0x3f3f3f3f;
const ll infll = 0x3f3f3f3f3f3f3f3fLL;
inline ll read()
{
ll x=0,f=1;char ch=getchar();
while(ch<‘0‘||ch>‘9‘){if(ch==‘-‘)f=-1;ch=getchar();}
while(ch>=‘0‘&&ch<=‘9‘){x=x*10+ch-‘0‘;ch=getchar();}
return x*f;
}
//**************************************************************************************
struct node
{
int l,r;
int ma;
};
node a[maxn*4];
int num[maxn];
void build(int x,int l,int r)
{
a[x].l=l,a[x].r=r;
if(l==r)
{
a[x].ma=num[l];
return;
}
int mid=(l+r)>>1;
build(x<<1,l,mid);
build(x<<1|1,mid+1,r);
a[x].ma=max(a[x<<1].ma,a[x<<1|1].ma);
}
int query(int x,int l,int r)
{
int L=a[x].l,R=a[x].r;
if(l<=L&&R<=r)
return a[x].ma;
int mid=(a[x].l+a[x].r)>>1;
if(r<=mid)
return query(x<<1,l,r);
if(l>mid)
return query(x<<1|1,l,r);
return max(query(x<<1,l,mid),query(x<<1|1,mid+1,r));
}
int main()
{
int t=read();
while(t--)
{
memset(a,0,sizeof(a));
int n=read();
for(int i=1;i<=n;i++)
num[i]=read();
build(1,1,n);
int q=read();
for(int i=0;i<q;i++)
{
int l=read(),r=read();
printf("%d\n",query(1,l,r));
}
}
}