// moreflags=grader.cpp
// ...
// segment tree delazification is a good idea.
// this is just a little faster.
#include "seats.h"
#include<vector>
#include<climits>
#include<algorithm>
#if LOCAL
#include<iostream>
#else
#define NDEBUG
#endif
#include<cassert>
struct Tree{
struct T{
int pminimum, count, sum;
void operator+=(T other) {
if(other.count==0) return;
other.pminimum+=sum;
sum+=other.sum;
if(pminimum<other.pminimum){
}else if(pminimum==other.pminimum){
count+=other.count;
}else{
count=other.count; pminimum=other.pminimum;
}
}
friend T operator+(T first, T sec){first+=sec; return first;}
};
std::vector<T> data;
Tree(){}
Tree(int number): data(4<<(31^__builtin_clz(number)), {INT_MAX, 0, INT_MAX}){ // this tree is order-sensitive.
}
void build(){
for(int node=int(data.size()/2); --node;)
data[node]=data[node*2]+data[node*2+1];
}
void addSuffix(int left, int value){
left+=int(data.size()/2);
assert(data[left].count==1);
assert(data[left].pminimum==data[left].sum);
data[left].pminimum=data[left].sum+=value;
for(left>>=1; left; left>>=1)
data[left]=data[left*2]+data[left*2+1];
}
int get()const{
// operator+ is commutative
auto const d=data[1];
assert(d.pminimum>=4);
return d.pminimum==4 ? d.count: 0;
}
};
struct MyData{
MyData(){}
//int width;
std::vector<std::vector<int>> value; // pos -> time (in 0..H*W), with padded (H*W) values
struct Pos{ int row, col; };
std::vector<Pos> pos; // time -> pos
Tree tree;
template<int factor> void addTree_(Pos minimum, auto handler){
auto const [r, c]=minimum;
std::array<int, 4> times{{
value[r][c],
value[r+1][c],
value[r][c+1],
value[r+1][c+1],
}};
std::sort(begin(times), end(times));
auto const TOP=int(pos.size());
assert(times[0]<TOP); handler(times[0], factor);
if(times[1]==TOP) return; handler(times[1], -factor);
if(times[2]==TOP) return; handler(times[2], factor*5);
if(times[3]==TOP) return; handler(times[3], -factor*5);
// 5 is always greater than 4 => impossible
}
template<int factor> void addTreeMemory(Pos minimum){
addTree_<factor>(minimum, [&](int a, int b){ freeMemory[a]+=b; });
}
template<int factor> void addTreeMemoryIndices(Pos minimum){
addTree_<factor>(minimum, [&](int a, int b){
if(freeMemory[a]==0) freeIndices.push_back(a);
freeMemory[a]+=b;
});
}
std::vector<int> freeMemory; // :)
std::vector<int> freeIndices;
MyData(int const H, int const W, std::vector<int> const& R_, std::vector<int> const& C_):
value(H+2, std::vector<int>(W+2, H*W)),
pos(H*W), tree(H*W), freeMemory(H*W)
{
for(int time=0; time<H*W; ++time){
pos[time]={R_[time], C_[time]};
value[R_[time]+1][C_[time]+1]=time;
}
for(int i=0; i<(int)value.size()-1; ++i)
for(int j=0; j<(int)value[0].size()-1; ++j){
addTreeMemory<1>({i, j});
}
assert(freeMemory.size()<=tree.data.size()/2);
for(int a=0; a<(int)freeMemory.size(); ++a){
tree.data[a+int(tree.data.size()/2)]={freeMemory[a], 1, freeMemory[a]};
freeMemory[a]=0;
}
tree.build();
}
int swap(int first, int sec){
std::swap(pos[first], pos[sec]);
std::array<std::array<int, 2> /* can be Pos too if it has comparison operators */, 8> minimums{{
{pos[first].row, pos[first].col},
{pos[first].row, pos[first].col+1},
{pos[first].row+1, pos[first].col},
{pos[first].row+1, pos[first].col+1},
{pos[sec].row, pos[sec].col},
{pos[sec].row, pos[sec].col+1},
{pos[sec].row+1, pos[sec].col},
{pos[sec].row+1, pos[sec].col+1},
}};
std::sort(begin(minimums), end(minimums));
auto const last=std::unique(begin(minimums), end(minimums));
std::for_each(minimums.begin(), last, [&](auto it){
addTreeMemoryIndices<-1>({it[0], it[1]});
});
value[pos[first].row+1][pos[first].col+1]=first;
value[pos[sec].row+1][pos[sec].col+1]=sec;
std::for_each(minimums.begin(), last, [&](auto it){
addTreeMemoryIndices<1>({it[0], it[1]});
});
for(auto a: freeIndices) if(auto& l=freeMemory[a]){
tree.addSuffix(a, l);
l=0;
}
freeIndices.clear();
return tree.get();
}
} myData;
void give_initial_chart(int H, int W, std::vector<int> R, std::vector<int> C) {
myData=MyData{H, W, std::move(R), std::move(C)};
}
int swap_seats(int a, int b) {
return myData.swap(a, b);
}
