Window Area[USACO]

 

用线性表实现的。算覆盖面积的时候，每次从当前矩形向后扫描最多被后一个矩形分成n1（n1<=4）个小的矩形，然后这n个小的矩形再分别计算被下下个矩形覆盖后形成了n2个新的矩形...

开始把b 和 t 的操作给搞反了，还有就是定义的nTop 先把它往纵坐标理解的，写着写着突然脑抽了一下，把它当行号给理解了。结果关于top的判断就错了一半...。

第4次才提交通过.

 

/*
ID: zhangyc1
LANG: C++
TASK: window
*/
#include <string>
#include <cstring>
#include <cstdlib>
#include <cstdio>
#include <cmath>
#include <queue>
using namespace std;

struct SRectangle
{
    int nLeft, nRight, nTop, nBottom;
    SRectangle(){}
    SRectangle(int xl, int xr, int yt, int yb):nLeft(xl),nRight(xr),nTop(yt),nBottom(yb){}
};
struct SRectangleEx : SRectangle
{
    int nID;
    SRectangleEx(int n):nID(n){}
};

struct SLink;
SLink *pHead = NULL, *pTail = NULL;
struct SLink
{
    SRectangleEx* pRect;
    SLink *pNext, *pPre;
    SLink(SRectangleEx* p):pRect(p), pPre(pTail), pNext(NULL){}
};

SLink* arrLinkAdd[100];
char chAct, chID;
int nX1, nX2, nY1, nY2;
SLink** ppLink = &pHead;

inline void swap (int &a, int &b){ int temp = a; a = b; b = temp;}

void RemoveLink(SLink* pLink)
{
    if (pLink->pPre)
        pLink->pPre->pNext = pLink->pNext;
    else
        pHead = pLink->pNext;

    if (pLink->pNext)
        pLink->pNext->pPre = pLink->pPre;
    else
        pTail = pLink->pPre;
    pLink->pNext = NULL;
    pLink->pPre = NULL;
}

void prepairData()
{
    char buf[100];
    int nID;
    while (scanf("%c(%c", &chAct, &chID) > 0)
    {
        nID = chID - '0';
        switch (chAct)
        {
        case 'w':
            {
                SRectangleEx* pRect = new SRectangleEx(nID);
                scanf(",%d,%d,%d,%d",&pRect->nLeft,&pRect->nTop,&pRect->nRight,&pRect->nBottom);
                if (pRect->nLeft > pRect->nRight) swap(pRect->nLeft, pRect->nRight);
                if (pRect->nTop < pRect->nBottom) swap(pRect->nTop, pRect->nBottom);
                SLink* pLink = new SLink(pRect);
                arrLinkAdd[nID] = pLink; // 索引矩形
                *ppLink = pLink; // 链入尾部
                ppLink = &pLink->pNext;
                pTail = pLink;
            }
            break;
        case 'b':
            {
                SLink* pLink = arrLinkAdd[nID];
                RemoveLink(pLink);
                if (pHead)
                    pHead->pPre = pLink;
                else
                    pTail = pLink;
                pLink->pNext = pHead;
                pHead = pLink;
                ppLink = &pTail->pNext;// 更新插入用的二重指针
            }
            break;
        case 't':
            {
                SLink* pLink = arrLinkAdd[nID];
                RemoveLink(pLink);
                if (pTail)
                    pTail->pNext = pLink;
                else
                    pHead = pLink;
                pLink->pPre = pTail;
                pTail = pLink;
                ppLink = &pTail->pNext;// 更新插入用的二重指针
            }
            break;
        case  'd':
            {
                SLink* pLink = arrLinkAdd[nID];
                RemoveLink(pLink);
                if (pTail)
                    ppLink = &pTail->pNext;
                else
                    ppLink = &pHead;
            }
            break;
        case 's':
            {
                SLink* pLink = arrLinkAdd[nID];
                double dbArea = (pLink->pRect->nTop - pLink->pRect->nBottom)*(pLink->pRect->nRight - pLink->pRect->nLeft);
                SRectangle sRectangle(pLink->pRect->nLeft, pLink->pRect->nRight, pLink->pRect->nTop, pLink->pRect->nBottom);
                queue<SRectangle> Q;
                Q.push(sRectangle);
                pLink = pLink->pNext;
                while (pLink)
                {
                    int nSize = Q.size();
                    SRectangle subRect;
                    for (int i = 0; i < nSize; i++)
                    {
                        sRectangle = Q.front();
                        Q.pop();
                        // 上
                        if (pLink->pRect->nTop < sRectangle.nTop)
                        {
                            subRect.nLeft = sRectangle.nLeft; subRect.nRight = sRectangle.nRight;
                            subRect.nTop = sRectangle.nTop; subRect.nBottom = max(pLink->pRect->nTop, sRectangle.nBottom);
                            Q.push(subRect);
                        }
                        // 下
                        if (pLink->pRect->nBottom > sRectangle.nBottom)
                        {
                            subRect.nLeft = sRectangle.nLeft; subRect.nRight = sRectangle.nRight;
                            subRect.nTop = min(sRectangle.nTop, pLink->pRect->nBottom); subRect.nBottom = sRectangle.nBottom;
                            Q.push(subRect);
                        }
                        // 左
                        if (pLink->pRect->nLeft > sRectangle.nLeft)
                        {
                            subRect.nLeft = sRectangle.nLeft;
                            subRect.nRight = min(pLink->pRect->nLeft, sRectangle.nRight);
                            subRect.nTop = min(sRectangle.nTop, pLink->pRect->nTop);
                            subRect.nBottom = max(sRectangle.nBottom, pLink->pRect->nBottom);
                            if (subRect.nTop > subRect.nBottom)
                                Q.push(subRect);
                        }
                        // 右
                        if (pLink->pRect->nRight < sRectangle.nRight)
                        {
                            subRect.nRight = sRectangle.nRight;
                            subRect.nLeft = max(pLink->pRect->nRight, sRectangle.nLeft);
                            subRect.nTop = min(sRectangle.nTop, pLink->pRect->nTop);
                            subRect.nBottom = max(sRectangle.nBottom, pLink->pRect->nBottom);
                            if (subRect.nTop > subRect.nBottom)
                                Q.push(subRect);
                        }
                    }
                    pLink = pLink->pNext;
                }
                
                double dbLeft = 0;
                while (!Q.empty())
                {
                    sRectangle = Q.front();
                    Q.pop();
                    dbLeft += (sRectangle.nTop - sRectangle.nBottom) * (sRectangle.nRight - sRectangle.nLeft);
                }
                printf("%.3lf\n", dbLeft * 100 / dbArea);
            }
            break;
        }
        while (getchar() != '\n');
    }
}

void process()
{
}

int main(){
    FILE *streamIn = freopen("window.in","r",stdin);
    FILE *streamOut = freopen("window.out","w",stdout);
    prepairData();
    process();
    fclose(streamIn);
    fclose(streamOut);
    return 0;
}