UVA 11020 (Lower_bound of efficient Solutions-multiset)

C + + Multiset, can be re-set:

S.lower_bound () The element that points to the first ai>=k of an iterator

S.upper_bound () The element that points to the first ai>k of an iterator

The subject can be translated into: There are N point coordinates (a, B)

no point on the first plane, each time you add a point to it, ask how many points each time, not in its lower left corner (excluding this point) (x ' <x,y ' <=y| | X ' <=x,y ' <y)

If p.a<a.a| | (P.A==A.A&&P.B<A.B), the other P<a

Obviously one point does not meet the condition, and thereafter it will not meet the condition, and if it can delete B, the point in its lower left corner can also be deleted

So you can remove points from the point set that don't meet the criteria.

Suppose the current point set a1<a2< <an

There are 2 different cases:

1:p does not meet the criteria.

2:p the point in the upper right corner of the P-match condition

#include <cstdio> #include <cstring> #include <cstdlib> #include <algorithm> #include < functional> #include <iostream> #include <cmath> #include <cctype> #include <ctime> #include <set>using namespace std; #define for (I,n) for (int. i=1;i<=n;i++) #define FORK (i,k,n) for (int i=k;i<=n;i++) # Define REP (I,n) for (int. i=0;i<n;i++) #define ForD (I,n) for (int. i=n;i;i--) #define REPD (i,n) for (int i=n;i>=0;i--) # Define Forp (x) for (int p=pre[x];p, p=next[p]) #define FORPITER (x) for (int &p=iter[x];p; p=next[p]) #define Lson (x< <1) #define Rson ((x<<1) +1) #define MEM (a) memset (A,0,sizeof (a)), #define MEMI (a) memset (A,127,sizeof (a)); Define Memi (a) memset (A,128,sizeof (a)), #define INF (2139062143) #define F (100000007) #define MAXT (40+10) #define MAXN ( 15000+10) long long mul (long long A,long long B) {return (a*b)%F;} Long Long (long A,long long B) {return (a+b)%F;} Long Long sub (long A,long long B) {return (a-b+ (a)/f*f+f)%F;} typedef LONGLong Ll;struct point{int A, B; Point () {}point (int _a,int _b): A (_a), B (_b) {}bool operator< (const point& RHS) Const{return a<rhs.a| | (a==rhs.a&&b<rhs.b);}}; Multiset<point> s;multiset<point>::iterator it;int n;int Main () {//freopen ("uva11020.in", "R", stdin);// Freopen (". Out", "w", stdout); int t;cin>>t;for (int. t=1;t<=t;t++) {printf ("Case #%d:\n", T);cin>>n; S.clear (); while (n--) {int a,b;scanf ("%d%d", &a,&b); Point P=point (A, b); It=s.lower_bound (P); Ai>=kif (It==s.begin () | | (--it)->b>b) {S.insert (P); It=s.upper_bound (P);//ai>kwhile (It!=s.end () &&it->b >= b) S.erase ( it++);} printf ("%d\n", S.size ());} if (t^t) Putchar (' \ n ');} return 0;}

UVA 11020 (Lower_bound of efficient Solutions-multiset)