Xiongnu's Land(扫描线)

#include <iostream>
#include <string>
#include <cstring>
#include <cstdio>
#include <bits/stdc++.h>
#define mst(a,b) memset(a,b,sizeof(a))
#define INF 0x3f3f3f3f
using namespace std;
typedef long long LL;
const int maxn=10000000+3;
const int mod=1000000007;
struct node
{
    LL L,T,W,H;
};
int n;
LL x[maxn];
LL sum[maxn];
LL allsum=0;
struct node oase[maxn];
int main()
{
    ios::sync_with_stdio(0);
    //freopen("in.txt","r",stdin);
    int k,r;
    cin>>k;
    while(k--)
    {
//        scanf("%d",&r);
//        scanf("%d",&n);
        cin>>r>>n;
        mst(sum,0);
        mst(x,0);
        allsum=0;
        for(int i=0; i<n; i++)
        {
//            scanf("%d%d%d%d",&oase[i].L,&oase[i].T,&oase[i].W,&oase[i].H);
            cin>>oase[i].L>>oase[i].T>>oase[i].W>>oase[i].H;
            //cout<<oase[i].L<<endl;
            allsum+=oase[i].W*oase[i].H;
            for(int j=oase[i].L; j<oase[i].W+oase[i].L; j++)
            {
                x[j]+=oase[i].H;
            }
        }
//        printf("allsum=%d\n",allsum);
        int i=0;
        LL sum=0;
        for(i=0; 2*sum<allsum; i++)
        {
            sum+=x[i];
            //printf("sum[%d]=%d\n",i,sum[i]);
        }
        while(x[i]==0&&i<r)
            i++;
        cout<<i<<endl;
    }
    return 0;
}