poj1434 Fill the Cisterns!

 1 #include <cstdio>
 2 #include <algorithm>
 3 #include <cstring>
 4 #include <cmath>
 5 
 6 using namespace std;
 7 
 8 #define MP make_pair
 9 #define PB push_back
10 #define lc (o<<1)
11 #define rc (o<<1|1)
12 typedef long long LL;
13 typedef pair<int,int> PII;
14 const double eps=1e-8;
15 const double pi=acos(-1.0);
16 const int K=5e4+7;
17 const int mod=1e9+7;
18 
19 struct node
20 {
21     double b,h,s;
22     bool operator < (const node &ta) const
23     {
24         return b<ta.b;
25     }
26 }cis[K];
27 int n;
28 double v;
29 int sgn(double ta,double tb)
30 {
31     if(fabs(ta-tb)<eps) return 0;
32     return ta<tb?-1:1;
33 }
34 bool check(double x)
35 {
36     double ret=0;
37     for(int i=1;i<=n;i++)
38     {
39         if(sgn(cis[i].b,x)>0)  break;
40         ret+=cis[i].s*min(cis[i].h,x-cis[i].b);
41     }
42     return sgn(ret,v)>=0;
43 }
44 int main(void)
45 {
46     int t;
47     scanf("%d",&t);
48     while(t--)
49     {
50         scanf("%d",&n);
51         double sum=0,l=1e9,r=-1e9;
52         for(int i=1;i<=n;i++)
53         {
54             double b,h,w,d;
55             scanf("%lf%lf%lf%lf",&b,&h,&w,&d);
56             cis[i]=(node){b,h,w*d};
57             sum+=h*w*d;
58             l=min(l,b),r=max(r,b+h);
59         }
60         sort(cis+1,cis+1+n);
61         scanf("%lf",&v);
62         if(sgn(v,sum)>0)
63         {
64             printf("OVERFLOW\n");
65             continue;
66         }
67         while(r-l>0.001)
68         {
69             double mid=(l+r)/2;
70             if(check(mid))
71                 r=mid;
72             else
73                 l=mid;
74         }
75         printf("%.2f\n",l);
76     }
77     return 0;
78 }