HDU 5857 Median——模拟

#include <cstdio>
#include <iostream>
#include <algorithm>
using namespace std;

int n,m;
int a[100010];
int l1,r1,l2,r2;
int solve(int len)
{
    if(r1 <= l2)
    {
        if(r1-l1+1 >= len) return a[l1+len-1];
        else
        {
            len -= r1 - l1 + 1; return a[l2+len-1];
        }
    }
    else
    {
        if(l2-l1 >= len) return a[l1+len-1];
        else if(l2-l1+(r1-l2+1)*2 < len)
        {
            len -= r1-l1+1; return a[l2+len-1];
        }
        else
        {
            len -= l2 - l1;
            if(len & 1) return a[l2+len/2];
            else return a[l2+len/2-1];
        }
    }
}

int main()
{
    int t; scanf("%d",&t);
    while(t--)
    {
        scanf("%d%d",&n,&m);
        for(int i = 1; i <= n; i++) scanf("%d",&a[i]);
        while(m--)
        {
            scanf("%d%d%d%d",&l1,&r1,&l2,&r2);
            if(l1 > l2) swap(l1,l2);
            if(r1 > r2) swap(r1,r2);
            int len = r1 - l1 + 1 + r2 - l2 + 1;
            if(len & 1) printf("%.1f\n",1.0*solve(len/2+1));
            else printf("%.1f\n",0.5*solve(len/2)+0.5*solve(len/2+1));
        }
    }
    return 0;
}