HDU-1255 覆盖的面积 覆盖的矩形面积并
题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=1255
需要保存区间覆盖线>=2的线段的长度,根据情况来更新。。。
1 //STATUS:C++_AC_250MS_476KB 2 #include <functional> 3 #include <algorithm> 4 #include <iostream> 5 //#include <ext/rope> 6 #include <fstream> 7 #include <sstream> 8 #include <iomanip> 9 #include <numeric> 10 #include <cstring> 11 #include <cassert> 12 #include <cstdio> 13 #include <string> 14 #include <vector> 15 #include <bitset> 16 #include <queue> 17 #include <stack> 18 #include <cmath> 19 #include <ctime> 20 #include <list> 21 #include <set> 22 #include <map> 23 using namespace std; 24 //using namespace __gnu_cxx; 25 //define 26 #define pii pair<int,int> 27 #define mem(a,b) memset(a,b,sizeof(a)) 28 #define lson l,mid,rt<<1 29 #define rson mid+1,r,rt<<1|1 30 #define PI acos(-1.0) 31 //typedef 32 typedef __int64 LL; 33 typedef unsigned __int64 ULL; 34 //const 35 const int N=2010; 36 const int INF=0x3f3f3f3f; 37 const int MOD=100000,STA=8000010; 38 const LL LNF=1LL<<60; 39 const double EPS=1e-8; 40 const double OO=1e15; 41 const int dx[4]={-1,0,1,0}; 42 const int dy[4]={0,1,0,-1}; 43 const int day[13]={0,31,28,31,30,31,30,31,31,30,31,30,31}; 44 //Daily Use ... 45 inline int sign(double x){return (x>EPS)-(x<-EPS);} 46 template<class T> T gcd(T a,T b){return b?gcd(b,a%b):a;} 47 template<class T> T lcm(T a,T b){return a/gcd(a,b)*b;} 48 template<class T> inline T lcm(T a,T b,T d){return a/d*b;} 49 template<class T> inline T Min(T a,T b){return a<b?a:b;} 50 template<class T> inline T Max(T a,T b){return a>b?a:b;} 51 template<class T> inline T Min(T a,T b,T c){return min(min(a, b),c);} 52 template<class T> inline T Max(T a,T b,T c){return max(max(a, b),c);} 53 template<class T> inline T Min(T a,T b,T c,T d){return min(min(a, b),min(c,d));} 54 template<class T> inline T Max(T a,T b,T c,T d){return max(max(a, b),max(c,d));} 55 //End 56 57 struct Seg{ 58 double y,x1,x2; 59 int c; 60 Seg(){} 61 Seg(double a,double b,double c,int d):y(a),x1(b),x2(c),c(d){} 62 bool operator < (const Seg& a)const{ 63 return y<a.y; 64 } 65 }seg[N]; 66 double hs[N],len[N<<2][2]; 67 int cnt[N<<2]; 68 int T,n,m; 69 70 void pushup(int l,int r,int rt) 71 { 72 if(cnt[rt])len[rt][0]=hs[r+1]-hs[l]; 73 else if(l==r)len[rt][0]=0; 74 else len[rt][0]=len[rt<<1][0]+len[rt<<1|1][0]; 75 if(cnt[rt]>=2)len[rt][1]=len[rt][0]; 76 else if(cnt[rt]==1)len[rt][1]=len[rt<<1][0]+len[rt<<1|1][0]; 77 else if(l==r)len[rt][1]=0; 78 else len[rt][1]=len[rt<<1][1]+len[rt<<1|1][1]; 79 } 80 81 void update(int a,int b,int c,int l,int r,int rt) 82 { 83 if(a<=l && r<=b){ 84 cnt[rt]+=c; 85 pushup(l,r,rt); 86 return; 87 } 88 int mid=(l+r)>>1; 89 if(a<=mid)update(a,b,c,lson); 90 if(b>mid)update(a,b,c,rson); 91 pushup(l,r,rt); 92 } 93 94 int binary(int l,int r,double tar) 95 { 96 int mid; 97 while(l<r){ 98 mid=(l+r)>>1; 99 if(hs[mid]==tar)return mid; 100 else if(hs[mid]>tar)r=mid; 101 else l=mid+1; 102 } 103 return -1; 104 } 105 106 int main() 107 { 108 // freopen("in.txt","r",stdin); 109 int i,j,k,l,r; 110 double ans,a,b,c,d; 111 scanf("%d",&T); 112 while(T--) 113 { 114 scanf("%d",&n); 115 m=0; 116 for(i=0;i<n;i++){ 117 scanf("%lf%lf%lf%lf",&a,&b,&c,&d); 118 hs[m]=a; 119 seg[m++]=Seg(b,a,c,1); 120 hs[m]=c; 121 seg[m++]=Seg(d,a,c,-1); 122 } 123 sort(hs,hs+m); 124 sort(seg,seg+m); 125 for(i=1,k=0;i<m;i++) 126 if(hs[i]!=hs[k])hs[++k]=hs[i]; 127 mem(len,0);mem(cnt,0); 128 ans=0; 129 for(i=0;i<m-1;i++){ 130 l=binary(0,k+1,seg[i].x1); 131 r=binary(0,k+1,seg[i].x2)-1; 132 if(l<=r)update(l,r,seg[i].c,0,k,1); 133 ans+=len[1][1]*(seg[i+1].y-seg[i].y); 134 } 135 136 printf("%.2lf\n",ans); 137 } 138 return 0; 139 }