tjut 1542

来源：互联网发布：淘宝食品类目规则编辑：程序博客网时间：2024/06/15 06:47
#include <iostream>#include <algorithm>using namespace std;const int maxn=110;struct LINE{    double  x, y_down, y_up;    int  flag;    bool operator<(const LINE &a)const    {        return  x<a.x;    }}line[2*maxn];struct TREE{    double  y_down, y_up;    double  x;    int     cover; //用以表示加进线段树中的线段次数    bool    flag; //此标记用来表示是否有超元线段；为了处理方便加上去的}tree[1000*maxn];int     n;double  x1, y1, x2, y2;int     index1=0;double  y[2*maxn];void build(int i, int l, int r){    tree[i].x = -1; //-1表示该区间已经没有线段    tree[i].cover = 0; //表示该区间上有多少条线段；左边线段加进去则++，右边线段加进去则--    tree[i].y_down = y[l];    tree[i].y_up = y[r];    tree[i].flag = false;    if(l+1==r)    {        tree[i].flag = true; //flag==true表示达到了叶子节点        return;    }    int mid=(l+r)>>1;    build(2*i, l, mid);    build(2*i+1, mid, r);}double insert(int i, double x, double l, double r, int flag) //flag表示为左边还是右边{    if (r<=tree[i].y_down || l>=tree[i].y_up)        return 0;    if (tree[i].flag)    {        if (tree[i].cover > 0) //递归到了叶子节点        {            double temp_x = tree[i].x;            double ans=(x-temp_x)*(tree[i].y_up - tree[i].y_down);            tree[i].x = x;   //定位上一次的x            tree[i].cover += flag;            return ans;        }        else        {            tree[i].cover += flag;            tree[i].x = x;            return 0;        }    }    double ans1, ans2;    ans1 = insert(2*i, x, l, r, flag);    ans2 = insert(2*i+1, x, l, r, flag);    return ans1+ans2;}int main( ){    // freopen("d:\\in.txt","r",stdin);    int  count=0;    while (scanf("%d", &n)!=EOF&&n)    {        index1 = 1;        for (int i=1; i<=n; i++)        {            scanf("%lf%lf%lf%lf", &x1, &y1, &x2, &y2);            y[index1] = y1;            line[index1].x = x1;            line[index1].y_down = y1;            line[index1].y_up = y2;            line[index1].flag = 1; //1表示左边                        index1++;            y[index1] = y2;            line[index1].x = x2;            line[index1].y_down = y1;            line[index1].y_up = y2;            line[index1].flag = -1; //-1表示右边            index1++;        }        sort(&y[1], &y[index1]); //把所有的纵坐标按从小到大排序,把1写成了0，WA一次        sort(&line[1], &line[index1]);        build(1, 1, index1-1);        double ans=0;        int i;        for (i=1;i<index1;i++)        {            ans += insert(1, line[i].x, line[i].y_down, line[i].y_up, line[i].flag);        }        printf("Test case #%d\nTotal explored area: %.2f\n\n", ++count, ans);    }    return 0;}
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