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;
}