hdu517 Triple
Time Limit: 12000/6000 MS (Java/Others) Memory Limit: 65536/65536 K (Java/Others)
Total Submission(s): 160 Accepted Submission(s): 72
Total Submission(s): 160 Accepted Submission(s): 72
Problem Description
Given the finite multi-set A of n pairs
of integers, an another finite multi-set B of m triples
of integers, we define the product of A and B as
a multi-set
C=A∗B={⟨a,c,d⟩∣⟨a,b⟩∈A, ⟨c,d,e⟩∈B and b=e}
For each ⟨a,b,c⟩∈C, its BETTER set is defined as
BETTERC(⟨a,b,c⟩)={⟨u,v,w⟩∈C∣⟨u,v,w⟩≠⟨a,b,c⟩, u≥a, v≥b, w≥c}
As a \textbf{multi-set} of triples, we define the TOP subset (as a multi-set as well) of C, denoted by TOP(C), as
TOP(C)={⟨a,b,c⟩∈C∣BETTERC(⟨a,b,c⟩)=∅}
You need to compute the size of TOP(C).
C=A∗B={⟨a,c,d⟩∣⟨a,b⟩∈A, ⟨c,d,e⟩∈B and b=e}
For each ⟨a,b,c⟩∈C, its BETTER set is defined as
BETTERC(⟨a,b,c⟩)={⟨u,v,w⟩∈C∣⟨u,v,w⟩≠⟨a,b,c⟩, u≥a, v≥b, w≥c}
As a \textbf{multi-set} of triples, we define the TOP subset (as a multi-set as well) of C, denoted by TOP(C), as
TOP(C)={⟨a,b,c⟩∈C∣BETTERC(⟨a,b,c⟩)=∅}
You need to compute the size of TOP(C).
Input
The input contains several test cases. The first line of the input is a single integer t (1≤t≤10) which
is the number of test case. Then t test
cases follow.
Each test case contains three lines. The first line contains two integers n (1≤n≤105) and m (1≤m≤105) corresponding to the size of A and B respectively.
The second line contains 2×n nonnegative integers
which describe the multi-set A, where 1≤ai,bi≤105.
The third line contains 3×m nonnegative integers
corresponding to the m triples of integers in B, where 1≤ci,di≤103 and 1≤ei≤105.
Each test case contains three lines. The first line contains two integers n (1≤n≤105) and m (1≤m≤105) corresponding to the size of A and B respectively.
The second line contains 2×n nonnegative integers
a1,b1,a2,b2,⋯,an,bn
which describe the multi-set A, where 1≤ai,bi≤105.
The third line contains 3×m nonnegative integers
c1,d1,e1,c2,d2,e3,⋯,cm,dm,em
corresponding to the m triples of integers in B, where 1≤ci,di≤103 and 1≤ei≤105.
Output
For each test case, you should output the size of set TOP(C).
Sample Input
2
5 9
1 1 2 2 3 3 3 3 4 2
1 4 1 2 2 1 4 1 1 1 3 2 3 2 2 4 1 2 2 4 3 3 2 3 4 1 3
3 4
2 7 2 7 2 7
1 4 7 2 3 7 3 2 7 4 1 7
Sample Output
Case #1: 5
Case #2: 12
思路:这题可以用二维树状数组做,先对二元组按y关键字升序排列,对三元组按z关键字升序排列,找出二元组中y相同的情况下最大的x及其个数,然后依次乘上三元组形成新的三元组并放入map中,用map记录三元组即其个数,便于后面统计方案。然后删去不合法的三元组,可以先对其按x,y,z一二三关键字降序排列,然后依次循环,这样首先保证x是递减的,然后如果在它右上方有点,那么这个点就要删除(即y,z都大于等于它),可以用树状数组实现。
#include<iostream>
#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<math.h>
#include<vector>
#include<map>
#include<set>
#include<queue>
#include<stack>
#include<string>
#include<algorithm>
using namespace std;
typedef long long ll;
#define inf 99999999
#define maxn 100050
int first[maxn],last[maxn],cnt[maxn],maxnum[maxn];
struct node1{
int x,y;
}a[maxn];
struct node2{
int x,y,z;
}c[maxn];
bool cmp(node1 a,node1 b){
if(a.y==b.y)return a.x>b.x;
return a.y<b.y;
}
bool cmp1(node2 a,node2 b){
return a.z<b.z;
}
struct node{
int x,y,z;
}temp,temp2;
bool operator<(node a,node b){
if(a.x==b.x){
if(a.y==b.y)return a.z>b.z;
return a.y>b.y;
}
return a.x>b.x;
}
map<node,int>mp;
map<node,int>::iterator it;
int b[1005][1005],pan[1006][1006];
int lowbit(int x){
return x&(-x);
}
void update(int x,int y,int num)
{
int i,j;
for(i=x;i<=1003;i+=lowbit(i)){
for(j=y;j<=1003;j+=lowbit(j)){
b[i][j]+=num;
}
}
}
int getsum(int x,int y)
{
int num=0,i,j;
for(i=x;i>0;i-=lowbit(i)){
for(j=y;j>0;j-=lowbit(j)){
num+=b[i][j];
}
}
return num;
}
int cal(int x,int y){
return getsum(1003,1003)-getsum(1003,y-1)-getsum(x-1,1003)+getsum(x-1,y-1);
}
int main()
{
int n,m,i,j,T,d,e,f,t,maxx,num,cas=0;
scanf("%d",&T);
while(T--)
{
scanf("%d%d",&n,&m);
for(i=1;i<=n;i++){
scanf("%d%d",&a[i].x,&a[i].y);
}
sort(a+1,a+n+1,cmp);
for(i=1;i<=m;i++){
scanf("%d%d%d",&c[i].x,&c[i].y,&c[i].z);
}
sort(c+1,c+m+1,cmp1);
memset(first,0,sizeof(first));
memset(last,0,sizeof(last));
t=c[1].z;
first[t]=1;
c[m+1].z=-1;
for(i=2;i<=m+1;i++){
if(c[i].z!=t ){
last[t]=i-1;
t=c[i].z;
first[t]=i;
}
}
memset(maxnum,-1,sizeof(maxnum));
memset(cnt,0,sizeof(cnt));
for(i=1;i<=n;i++){
if(maxnum[a[i].y ]==-1 ){
maxnum[a[i].y ]=a[i].x;
cnt[a[i].y ]=1;
}
else{
if(maxnum[a[i].y ]<a[i].x){
maxnum[a[i].y ]=a[i].x;
cnt[a[i].y ]=1;
}
else if(maxnum[a[i].y ]==a[i].x){
cnt[a[i].y ]++;
}
}
}
mp.clear();
for(i=1;i<=10000;i++){
if(maxnum[i ]!=-1 && first[i ]!=0 ){
for(j=first[i ];j<=last[i ];j++){
temp.x=maxnum[i];temp.y=c[j].x;temp.z=c[j].y;
mp[temp]+=cnt[i];
}
}
}
memset(b,0,sizeof(b));
memset(pan,0,sizeof(pan));
int ans=0;
for(it=mp.begin();it!=mp.end();it++){
temp=it->first;
int y=temp.y;
int z=temp.z;
if(pan[y][z]==0 && cal(y,z)==0){
ans+=it->second;
}
pan[y][z]=1;
update(y,z,1);
}
cas++;
printf("Case #%d: %d\n",cas,ans);
}
return 0;
}