HDU 4419 Colourful Rectangle --离散化+线段树扫描线

#include <iostream>
#include <cstdio>
#include <cstring>
#include <cstdlib>
#include <cmath>
#include <algorithm>
#define lll __int64
using namespace std;
#define N 10107

lll Len[7*N][8];
int cov[7*N][4];

struct Line
{
    int y1,y2,x;
    int col;
}line[2*N];
int yy[2*N];

int cmp(Line ka,Line kb) { return ka.x < kb.x; }

void pushup(int l,int r,int rt)
{
    int state = 0;
    for(int i=1;i<=3;i++) if(cov[rt][i]) state |= (1<<(i-1));  //表示此区间内有的颜色
    for(int i=0;i<8;i++)  Len[rt][i] = 0;                      //加了一层，要重新算各个颜色的长度
    if(l+1 == r)                                               //叶子节点
    {
        Len[rt][state] = yy[r]-yy[l];                          //只有此颜色state，长度为yy[r]-yy[l]
        return;
    }
    for(int i=0;i<8;i++)                                       //否则使用下面的更新
        Len[rt][i|state] += Len[2*rt][i] + Len[2*rt+1][i];
}

void build(int l,int r,int rt)
{
    for(int i=1;i<=3;i++) cov[rt][i] = 0;
    for(int i=1;i<8;i++)  Len[rt][i] = 0;
    Len[rt][0] = yy[r]-yy[l];
    if(l == r-1) return;
    int mid = (l+r)/2;
    build(l,mid,2*rt);
    build(mid,r,2*rt+1);
}

void update(int l,int r,int aa,int bb,int cover,int rt)
{
    if(aa <= l && bb >= r)
    {
        if(cover > 0) cov[rt][cover]++;
        else          cov[rt][-cover]--;
        pushup(l,r,rt);
        return;
    }
    if(l+1 == r) return;
    int mid = (l+r)/2;
    if(aa <= mid)
        update(l,mid,aa,bb,cover,2*rt);
    if(bb > mid)
        update(mid,r,aa,bb,cover,2*rt+1);
    pushup(l,r,rt);
}

int main()
{
    int n,m,t,cs = 1,i,j;
    int x1,y1,x2,y2,c;
    char ss[4];
    scanf("%d",&t);
    while(t--)
    {
        m = 1;
        scanf("%d",&n);
        for(i=0;i<n;i++)
        {
            scanf("%s%d%d%d%d",ss,&x1,&y1,&x2,&y2);
            if(ss[0] == ‘R‘)      c = 1;
            else if(ss[0] == ‘G‘) c = 2;
            else                  c = 3;
            line[m].x = x1,line[m].y1 = y1,line[m].y2 = y2,line[m].col = c,yy[m++] = y1;
            line[m].x = x2,line[m].y1 = y1,line[m].y2 = y2,line[m].col = -c,yy[m++] = y2;
        }
        m--;
        sort(yy+1,yy+m+1);
        int cnt = 2;
        for(i=2;i<=m;i++)
        {
            if(yy[i] != yy[i-1])
                yy[cnt++] = yy[i];
        }
        cnt--;
        build(1,cnt,1);
        sort(line+1,line+m+1,cmp);
        lll ans[8];
        memset(ans,0,sizeof(ans));
        printf("Case %d:\n",cs++);
        for(i=1;i<m;i++)
        {
            int L = lower_bound(yy+1,yy+cnt+1,line[i].y1)-yy;
            int R = upper_bound(yy+1,yy+cnt+1,line[i].y2)-yy-1;
            update(1,cnt,L,R,line[i].col,1);
            for(j=1;j<8;j++)
                ans[j] += Len[1][j]*(line[i+1].x-line[i].x);
        }
        printf("%I64d\n%I64d\n%I64d\n%I64d\n%I64d\n%I64d\n%I64d\n",ans[1],ans[2],ans[4],ans[3],ans[5],ans[6],ans[7]);
    }
    return 0;
}