poj 1151 Atlantis 二分查找+离散化

Description

Input

Output

Sample Input

2
10 10 20 20
15 15 25 25.5
0

Sample Output

Test case #1
Total explored area: 180.00 

I met several bugs:

1. printf("%.2f", res);  for double type instead of the setence printf("%.2lf", res);   because for g++, %lf is not supported, so we must use %f for output and %lf for input. 

2. Output a blank line after each test case.

#include <iostream>
#include <map>
#include <vector>
#include <algorithm>
#include <limits.h>
#include <assert.h>
#include <stdio.h>
using namespace std;


class Rec {
 public:
  double ltx, lty, rdx, rdy;
  Rec(double x1 = 0, double y1 = 0, double x2 = 0, double y2 = 0): ltx(x1), lty(y1), rdx(x2), rdy(y2){
  }
};
class Inte {
public:
  double s, e;  
  Inte(double s1 = 0, double e1 = 0) : s(s1), e(e1) {
  }
};
class cmp1 {
 public:
  bool operator()(const Inte& inte1, const Inte& inte2) const{
    return inte1.s == inte2.s ? inte1.e < inte2.e : inte1.s < inte2.s;
  }
};

class Solution{
 public:

  vector<Inte> merge(vector<Inte>& inte) {
    vector<Inte> res;
    if (inte.empty())
      return res;
    sort(inte.begin(), inte.end(), cmp1());

    Inte cur(inte[0].s, inte[0].e);
    int size = inte.size();
    for (int i = 1; i < size; ++i) {
      if (inte[i].s > cur.e) {
        res.push_back(cur);
        cur.s = inte[i].s, cur.e = inte[i].e;
      }
      else {
        cur.s = min(cur.s, inte[i].s);
        cur.e = max(cur.e, inte[i].e);
      }
    }
    res.push_back(cur);
    return res;
    
  }

  double calArea(vector<vector<Inte> >& inters, const vector<double>& xcoor) {
    double res = 0;
    int size = inters.size();
    for (int i = 0; i < size; ++i) {
      vector<Inte> cur = merge(inters[i]);

      int cursize = cur.size();
      for (int j = 0; j < cursize; ++j)
        res += (cur[j].e - cur[j].s)*(xcoor[i+1]-xcoor[i]);
    }
    return res;
  }
  double calAllArea(const vector<Rec>& recs) {
    int i, size = recs.size(), j, intesize;
    vector<double> xcoor;
    
    for (i = 0; i < size; ++i) {
      xcoor.push_back(recs[i].ltx);
      xcoor.push_back(recs[i].rdx);
    }
    sort(xcoor.begin(), xcoor.end());
    xcoor.resize(unique(xcoor.begin(), xcoor.end()) - xcoor.begin());
    intesize = xcoor.size() - 1;
    vector<vector<Inte> > inters(intesize, vector<Inte>(0));
    
    
    for (i = 0; i < size; ++i) {
      int j1 = lower_bound(xcoor.begin(), xcoor.end(), recs[i].ltx) - xcoor.begin();
      int j2 = upper_bound(xcoor.begin(), xcoor.end(), recs[i].rdx) - xcoor.begin();
      for (j = j1; j <= j2 -2; ++j) {
        inters[j].push_back( Inte(recs[i].rdy, recs[i].lty));
      }
    }
    double res = calArea(inters, xcoor);
    return res;
  }
};
int main()
{
  Solution s;
  freopen("E://test.txt","r",stdin);
  vector<Rec> recs;
  int k, count = 0;
  double x1, x2, y1, y2;
  while (scanf("%d", &k) && k != 0) {
    recs.resize(0);
    printf("Test case #%d\n", ++count);
    while (k--) {
      scanf("%lf%lf%lf%lf",&x1,&y1,&x2,&y2);
      recs.push_back(Rec(x1, y2, x2, y1));
    }
    double res = s.calAllArea(recs);
    printf("Total explored area: %.2f\n\n", res);    
  }
  return 0;
}

poj 1151 Atlantis 二分查找+离散化,布布扣,bubuko.com

poj 1151 Atlantis 二分查找+离散化

原文：http://blog.csdn.net/taoqick/article/details/38639795