#include "seats.h"
#include <bits/stdc++.h>
using namespace std;
#define fi first
#define se second
#define ll long long
#define ii pair<int,int>
#define INF (int)(1e9)
pair<ii,ii> tab[1000002];
int A[1000002],st[4000005],n;
vector<int> r,c;
void build(int node,int l,int r){
if(l==r){
st[node]=A[l];
return ;
}
int med=(l+r)/2;
build(node*2,l,med),build(node*2+1,med+1,r);
st[node]=st[node*2]+st[node*2+1];
}
void flip(int node,int l,int r,int idx){
if(r<idx||l>idx)
return ;
if(l==r){
st[node]=1-st[node];
return ;
}
int med=(l+r)/2;
flip(node*2,l,med,idx),flip(node*2+1,med+1,r,idx);
st[node]=st[node*2]+st[node*2+1];
}
void give_initial_chart(int H, int W, vector<int> R, vector<int> C) {
n=H*W;
r=R,c=C;
for (int i = 0; i < n; ++i)
{
tab[i].fi=ii(R[i],C[i]);
tab[i].se=ii(R[i],C[i]);
if(i){
tab[i].fi.fi=max(tab[i].fi.fi,tab[i-1].fi.fi);
tab[i].fi.se=max(tab[i].fi.se,tab[i-1].fi.se);
tab[i].se.fi=min(tab[i].se.fi,tab[i-1].se.fi);
tab[i].se.se=min(tab[i].se.se,tab[i-1].se.se);
}
if((tab[i].fi.fi-tab[i].se.fi+1)*(tab[i].fi.se-tab[i].se.se+1)==(i+1))A[i]=1;
else A[i]=0;
}
build(1,0,n-1);
//cerr<<st[1]<<"\n";
}
int swap_seats(int a, int b) {
swap(r[a],r[b]),swap(c[a],c[b]);
for (int i = min(a,b); i <= max(a,b); ++i)
{
tab[i].fi=ii(r[i],c[i]);
tab[i].se=ii(r[i],c[i]);
if(i){
tab[i].fi.fi=max(tab[i].fi.fi,tab[i-1].fi.fi);
tab[i].fi.se=max(tab[i].fi.se,tab[i-1].fi.se);
tab[i].se.fi=min(tab[i].se.fi,tab[i-1].se.fi);
tab[i].se.se=min(tab[i].se.se,tab[i-1].se.se);
}
if((tab[i].fi.fi-tab[i].se.fi+1)*(tab[i].fi.se-tab[i].se.se+1)==(i+1)){
if(!A[i])
A[i]=1,flip(1,0,n-1,i);
}
else {
if(A[i])
A[i]=0,flip(1,0,n-1,i);
}
}
return st[1];
}
