hiho 1249 Xiongnu's Land

分割线要满足三个条件：

1. 左边的绿洲面积要大于等于右边的绿洲面积。

2.两边的面积的差值要尽可能的小。

3.左边的总面积要尽可能的大于右边。

思路:先二分答案求出条件一和二满足的最左边的分割线，然后二分答案满足条件最右边的分割线。

本来写了一发线段树的，结果写搓了。。。。

#include<iostream>
#include<set>
#include<map>
#include<algorithm>
#include<cstdio>
#include<cstring>
#include<vector>
#include<queue>
#include<cmath>
using namespace std;
typedef long long ll;
const int maxn = 1000100;
int l[maxn], t[maxn], w[maxn], h[maxn], n;
/*void pushup(int cnt)
{
    sum[cnt] = sum[cnt<<1] + sum[cnt<<1|1];
}
void pushdown(int cnt, int len)

{
    if(mark[cnt])
    {
        int m = len / 2;
        mark[cnt<<1] += mark[cnt];
        mark[cnt<<1|1] += mark[cnt];
        sum[cnt<<1] += mark[cnt<<1] * (len - m);
        sum[cnt<<1|1] += mark[cnt<<1|1] * m;
        mark[cnt] = 0;
    }
}
void update(int nowl, int nowr, int l, int r, int c, int cnt)
{
    if(nowl>=l && nowr<=r)
    {
        sum[cnt] += (nowr - nowl + 1)*c;
        mark[cnt] += c;
        return ;
    }
    pushdown(cnt, nowr - nowl +1);
    int m = (nowr+nowl)>>1;
    if(l<=m)
        update(nowl, m, l, r, c, cnt<<1);
    if(r>m)
        update(m+1, nowr, l, r, c, cnt<<1|1);
    pushup(cnt);
}
ll query(int nowl, int nowr, int l, int r, int cnt)
{
    if(nowl>=l && nowr<=r)
    {
        return sum[cnt];
    }
    pushdown(cnt, nowr - nowl +1);
    int m = (nowl+nowr)>>1;
    ll sum = 0;
    if(l<=m)
        sum += query(nowl, m, l, r, cnt<<1);
    if(r>m)
        sum += query(m+1, nowr, l, r, cnt<<1|1);
    pushup(cnt);
    return sum;
}*/
ll get(int x)
{
    ll sum = 0;
    for(int i = 1; i<=n; i++)
    {
        sum += (ll)h[i]*(max(min(x-l[i], w[i]), 0));
    }
    return sum;
}
int main()
{
    int T;
    cin>>T;
    while(T--)
    {
        ll s = 0;
        int r;
        scanf("%d", &r);
        //memset(a, 0, sizeof(a));
        scanf("%d", &n);
        //  memset(mark, 0, sizeof(mark));
        //  memset(sum, 0, sizeof(sum));
        for(int i = 1; i<=n; i++)
        {
            scanf("%d%d%d%d", &l[i], &t[i], &w[i], &h[i]);
        }
        s = get(r);
        int right = r, left = 1, mid;
        while(left<=right)
        {
            mid = (right+left)>>1;
            ll sum =get(mid);
            if(sum >= s-sum)
            {
                right = mid - 1;
            }
            else
            {
                left = mid + 1;
            }
        }
         //cout<<left<<endl;
        ll ans = get(left);
        right = r, left = 1;
        //  cout<<ans<<endl;
        while(left <= right)
        {
            mid = (right+left)>>1;
            ll sum = get(mid);
            if(sum > ans)
            {
                right = mid-1;
            }
            else
            {
                left = mid+1;
            }
        }
        cout<<right<<endl;
    }
    return 0;
}