HDU Atlantis 线段树 表达区间

#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <algorithm>
#define IOS ios::sync_with_stdio(false)
using namespace std;
#define inf (0x3f3f3f3f)
typedef long long int LL;

#include <iostream>
#include <sstream>
#include <vector>
#include <set>
#include <map>
#include <queue>
#include <string>

int n;
const int maxn = 2e2 + 20;
struct node {
    int L, R;
    double x1, x2, y;
    int cover;
} seg[maxn << 2];
struct info {
    double x1, x2, y;
    int flag;
    bool operator < (const struct info & rhs) const {
        return y < rhs.y;
    }
} in[maxn];
double xx[maxn];
void build(int L, int R, int cur) {
    seg[cur].cover = 0;
    seg[cur].x1 = xx[L];
    seg[cur].x2 = xx[R];
    seg[cur].y = -1;
    seg[cur].L = L;
    seg[cur].R = R;
    if (L + 1 == R) { //两个节点作为一个叶子
        return;
    }
    int mid = (L + R) >> 1;
    build(L, mid, cur << 1);
    build(mid, R, cur << 1 | 1);
}
double upDate(int begin, int end, double y, int flag, int cur) {
    if (end <= seg[cur].L || begin >= seg[cur].R) return 0;
    if (seg[cur].L + 1 == seg[cur].R) {
        if (seg[cur].cover) {
            double ans = (seg[cur].x2 - seg[cur].x1) * (y - seg[cur].y);
            seg[cur].cover += flag;
            seg[cur].y = y;
            return ans;
        } else {
            seg[cur].cover += flag;
            seg[cur].y = y;
            return 0;
        }
    }
    double ans = upDate(begin, end, y, flag, cur << 1) + upDate(begin, end, y, flag, cur << 1 | 1);
    return ans;
}
void work() {
    int lenin = 0;
    int lenxx = 0;
    for (int i = 1; i <= n; ++i) {
        double xx1, xx2, yy1, yy2;
        scanf("%lf%lf%lf%lf", &xx1, &yy1, &xx2, &yy2);
        lenin++;
        in[lenin].x1 = xx1;
        in[lenin].x2 = xx2;
        in[lenin].y = yy1;
        in[lenin].flag = 1;
        lenxx++;
        xx[lenxx] = xx1;

        lenin++;
        in[lenin].x1 = xx1;
        in[lenin].x2 = xx2;
        in[lenin].y = yy2;
        in[lenin].flag = -1;
        lenxx++;
        xx[lenxx] = xx2;
    }
    sort(in + 1, in + 1 + lenin);
    sort(xx + 1, xx + 1 + lenxx);
    lenxx = unique(xx + 1, xx + 1 + lenxx) - (xx + 1);
    build(1, lenxx, 1);
    double ans = 0;
    const int root = 1;
    for (int i = 1; i <= lenxx; ++i) {
        printf("%f**\n", xx[i]);
    }
    for (int i = 1; i <= lenin; ++i) {
        int L = lower_bound(xx + 1, xx + 1 + lenxx, in[i].x1) - xx;
        int R = lower_bound(xx + 1, xx + 1 + lenxx, in[i].x2) - xx;
//        cout << L << " " << R << endl;
        ans += upDate(L, R, in[i].y, in[i].flag, root);
    }
    static int f = 0;
    printf("Test case #%d\n", ++f);
    printf("Total explored area: %0.2f\n", ans);
//    printf("%0.2f\n", ans);
}
int main() {
#ifdef local
    freopen("data.txt","r",stdin);
#endif
    while (scanf("%d", &n) != EOF && n) {
        work();
        printf("\n");
    }
    return 0;
}