UVA 511 Do You Know the Way to San Jose?

题目链接：https://vjudge.net/problem/UVA-511

题目翻译摘自《算法禁赛入门经典》

题目大意

　　有 n 张地图（已知名称和某两个对角线端点的坐标）和 m 个地名（已知名称和坐标）， 还有 q 个查询。每张地图都是边平行于坐标轴的矩形，比例定义为高度除以宽度的值。每个查询包含一个地名和详细等级 i。面积相同的地图总是属于同一个详细等级。假定包含此地名的地图中一共有 k 种不同的面积，则合法的详细等级为 1～k（其中 1 最不详细，k 最详细， 面积越小越详细）。如果详细等级 i 的地图不止一张，则输出地图中心和查询地名最接近的一张；如果还有并列的，地图长宽比应尽量接近 0.75（这是Web浏览器的比例）；如果还有并列，查询地名和地图右下角的坐标应最远（对应最少的滚动条移动）；如果还有并列，则输出x坐标最小的一个。如果查询的地名不存在或者没有地图包含它，应报告查询非法。如果包含它的地图最高详细等级小于 i，应报告查询非法（并输出包含它的最详细地图名称，如果存在）。

分析

　　对于每个询问，找出所有相关区域，然后用自定义比较器排一下序即可。

代码如下

 #include <bits/stdc++.h>
 using namespace std;

 #define INIT() ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
 #define Rep(i,n) for (int i = 0; i < (n); ++i)
 #define For(i,s,t) for (int i = (s); i <= (t); ++i)
 #define rFor(i,t,s) for (int i = (t); i >= (s); --i)
 #define ForLL(i, s, t) for (LL i = LL(s); i <= LL(t); ++i)
 #define rForLL(i, t, s) for (LL i = LL(t); i >= LL(s); --i)
 #define foreach(i,c) for (__typeof(c.begin()) i = c.begin(); i != c.end(); ++i)
 #define rforeach(i,c) for (__typeof(c.rbegin()) i = c.rbegin(); i != c.rend(); ++i)

 #define pr(x) cout << #x << " = " << x << "  "
 #define prln(x) cout << #x << " = " << x << endl

 #define LOWBIT(x) ((x)&(-x))

 #define ALL(x) x.begin(),x.end()
 #define INS(x) inserter(x,x.begin())
 #define UNIQUE(x) x.erase(unique(x.begin(), x.end()), x.end())
 #define REMOVE(x, c) x.erase(remove(x.begin(), x.end(), c), x.end()); // 删去 x 中所有 c
 #define TOLOWER(x) transform(x.begin(), x.end(), x.begin(),::tolower);
 #define TOUPPER(x) transform(x.begin(), x.end(), x.begin(),::toupper);

 #define ms0(a) memset(a,0,sizeof(a))
 #define msI(a) memset(a,inf,sizeof(a))
 #define msM(a) memset(a,-1,sizeof(a))

 #define MP make_pair
 #define PB push_back
 #define ft first
 #define sd second

 template<typename T1, typename T2>
 istream &operator>>(istream &in, pair<T1, T2> &p) {
     in >> p.first >> p.second;
     return in;
 }

 template<typename T>
 istream &operator>>(istream &in, vector<T> &v) {
     for (auto &x: v)
         in >> x;
     return in;
 }

 template<typename T1, typename T2>
 ostream &operator<<(ostream &out, const std::pair<T1, T2> &p) {
     out << "[" << p.first << ", " << p.second << "]" << "\n";
     return out;
 }

 inline int gc(){
     static const int BUF = 1e7;
     static char buf[BUF], *bg = buf + BUF, *ed = bg;

     if(bg == ed) fread(bg = buf, , BUF, stdin);
     return *bg++;
 } 

 inline int ri(){
     int x = , f = , c = gc();
     for(; c<||c>; f = c=='-'?-:f, c=gc());
     for(; c>&&c<; x = x* + c - , c=gc());
     return x*f;
 }

 template<class T>
 inline string toString(T x) {
     ostringstream sout;
     sout << x;
     return sout.str();
 }

 inline int toInt(string s) {
     int v;
     istringstream sin(s);
     sin >> v;
     return v;
 }

 //min <= aim <= max
 template<typename T>
 inline bool BETWEEN(const T aim, const T min, const T max) {
     return min <= aim && aim <= max;
 }

 typedef long long LL;
 typedef unsigned long long uLL;
 typedef pair< double, double > PDD;
 typedef pair< int, int > PII;
 typedef pair< int, PII > PIPII;
 typedef pair< string, int > PSI;
 typedef pair< int, PSI > PIPSI;
 typedef set< int > SI;
 typedef set< PII > SPII;
 typedef vector< int > VI;
 typedef vector< double > VD;
 typedef vector< VI > VVI;
 typedef vector< SI > VSI;
 typedef vector< PII > VPII;
 typedef map< int, int > MII;
 typedef map< int, string > MIS;
 typedef map< int, PII > MIPII;
 typedef map< PII, int > MPIII;
 typedef map< string, int > MSI;
 typedef map< string, string > MSS;
 typedef map< PII, string > MPIIS;
 typedef map< PII, PII > MPIIPII;
 typedef multimap< int, int > MMII;
 typedef multimap< string, int > MMSI;
 //typedef unordered_map< int, int > uMII;
 typedef pair< LL, LL > PLL;
 typedef vector< LL > VL;
 typedef vector< VL > VVL;
 typedef priority_queue< int > PQIMax;
 typedef priority_queue< int, VI, greater< int > > PQIMin;
 const double EPS = 1e-;
 const LL inf = 0x7fffffff;
 const LL infLL = 0x7fffffffffffffffLL;
 const LL mod = 1e9 + ;
 const int maxN = 1e4 + ;
 const LL ONE = ;
 const LL evenBits = 0xaaaaaaaaaaaaaaaa;
 const LL oddBits = 0x5555555555555555;

 int sgn(double x) {
     if(fabs(x) < EPS) return ;
     return x >  ?  : -;
 }

 double dist(PDD a,PDD b) {
   return sqrt((a.ft - b.ft) * (a.ft - b.ft) + (a.sd - b.sd) * (a.sd - b.sd));
 }

 struct MAP{
     double U, D, L, R, Area, ratio; // 上下左右和面积以及长宽比
     PDD center; // 中心点
     string name; 

     MAP() {}
     MAP(string s) {
         stringstream sin(s);
         double x1, y1, x2, y2;

         sin >> name >> x1 >> y1 >> x2 >> y2;
         L = min(x1, x2);
         R = max(x1, x2);
         U = max(y1, y2);
         D = min(y1, y2);
         center = MP((L + R) / , (U + D) / );
         Area = (R - L) * (U - D);
         ratio = fabs((R - L) / (U - D) - 0.75);
     }

     bool cover(PDD x) {
         return x.ft >= L && x.ft <= R && x.sd >= D && x.sd <= U;
     }

     bool operator< (const MAP &x) const {
         return Area > x.Area;
     }
 };
 vector< MAP > maps;

 string tmp;
 map< string, PDD > loc;
 string target;
 int level;

 struct MyCmp{
     bool operator() (const MAP &x, const MAP &y) const {
         PDD tar = loc[target];

         if(sgn(x.Area - y.Area) == ) {
             double a = dist(tar, x.center);
             double b = dist(tar, y.center);

             if(sgn(a - b) == ) {
                 if(sgn(x.ratio - y.ratio) == ) {
                     a = dist(tar, MP(x.R, x.D));
                     b = dist(tar, MP(y.R, y.D));

                     if(sgn(a - b) == ) return x.L < y.L;
                     return a > b;
                 }
                 return x.ratio < y.ratio;
             }
             return a < b;
         }
         return x.Area > y.Area;
     }
 }; 

 int main(){
     //freopen("MyOutput.txt","w",stdout);
     //freopen("input.txt","r",stdin);
     //INIT();
     getline(cin, tmp);
     while(getline(cin, tmp)) {
         if(tmp == "LOCATIONS") break;
         maps.PB(MAP(tmp));
     }

     while(getline(cin, tmp)) {
         if(tmp == "REQUESTS") break;
         stringstream sin(tmp);
         double x, y;

         sin >> tmp >> x >> y;
         loc[tmp] = MP(x, y);
     }

     while(getline(cin, tmp)) {
         if(tmp == "END") break;
         stringstream sin(tmp);

         sin >> target >> level;
         printf("%s at detail level %d ", target.c_str(), level);

         if(loc.find(target) == loc.end()) printf("unknown location\n");
         else {
             set< MAP, MyCmp > sm;
             // 找出所有包含target地点的map
             foreach(i, maps) if(i->cover(loc[target])) sm.insert(*i);

             if(sm.size() == ) printf("no map contains that location\n");
             else {
                 auto it = sm.begin();
                 double t = ;

                 while(it != sm.end()) {
                     if(it->Area != t) {
                         t = it->Area;
                         if(!--level) break;
                     }
                     ++it;
                 }

                 if(level) printf("no map at that detail level; using %s\n", sm.rbegin()->name.c_str());
                 else printf("using %s\n", it->name.c_str());
             }
         }
     }
     return ;
 }