// author lox:(
#pragma GCC optimize("O3")
#pragma GCC target("popcnt")
#include <bits/stdc++.h>
using namespace std;
#define IZhO_SILVER ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define popcnt __builtin_popcount
#define all(a) a.begin(),a.end()
#define low_b lower_bound
#define up_b upper_bound
#define vii vector<pair<ll,ll>>
#define vll vector<pair<ll,ll>>
#define pii pair<ll,ll>
#define mii map<ll,ll>
#define pll pair<ll,ll>
#define mll map<ll,ll>
#define vi vector<ll>
#define vl vector<ll>
#define pb push_back
#define endl '\n'
#define Y second
#define X first
typedef long double ld;
typedef long long ll;
const long long dx[4]={1,-1,0,0},dy[4]={0,0,1,-1},col=107,N=1e6+777;
const ll mod=1e9+7,inf=1e18;
void fre_open(){freopen("file.in","r",stdin);freopen("file.out","w",stdout);}
ll binpow(ll n,ll k){if(k<0)return 0ll;if(k==0)return 1ll;if(k%2)return (binpow(n,k-1)*n)%mod;ll kk=binpow(n,k/2)%mod;return (kk*kk)%mod;}
ll n,k;
pll gg[N];
void solve(){
cin>>n>>k;
if(k==0){
ll x=n*n/2;
for(ll i=n/2; i>=1; --i)if(n%i==0)x=min(x,i*i*((n/i)*(n/i)/2));
cout<<x;
return;
}
ll x=n*n/2;
ll x2=x+1;
for(ll c=0, i1,i2,j1,j2;c<k; ++c){
cin>>i1>>j1>>i2>>j2;
for(ll i=i1; i<=i2; ++i)
for(ll j=j1; j<=j2; ++j)
{
if(i%2==j%2) x++,x2--;
if(i%2!=j%2) x2++,x--;
}
}
cout<<min(x,x2);
return;
if(n<=1e5){
for(ll i=1; i<=k; ++i){
ll x,y,tox,toy;
cin>>x>>y>>tox>>toy;
gg[i]={x,y};
}
ll ans=mod-10;
for(ll d=1; d*d<=n; ++d){
if(n%d!=0) continue;
ll m=n/d;
ll res=(d*d)*((m*m)/2),res2;
res2=res+((m%2)*(d*d));
for(ll i=1; i<=k; ++i){
ll x,y;
tie(x,y)=gg[i];
x=(x+(d-1))/d;
y=(y+(d-1))/d;
if((x+y)%2==0){
res2--;
res++;
}
if((x+y)%2==1){
res--;
res2++;
}
}
ans=min({ans,res,res2});
m=n/(n/d);
res=((n/d)*(n/d))*((m*m)/2);
res2=res+(((m%2)*((n/d)*(n/d))));
for(ll i=1; i<=k; ++i){
ll x,y;
tie(x,y)=gg[i];
x=(x+((n/d)-1))/(n/d);
y=(y+((n/d)-1))/(n/d);
if((x+y)%2==0){
res2--;
res++;
}
if((x+y)%2==1){
res--;
res2++;
}
}
if(d==1){
ans=min(ans,max(res,res2));
continue;
}
ans=min({ans,res,res2});
}
cout<<ans<<endl;
return;
}
ll x=n*n/2;
ll x2=x+1;
for(ll c=0, i1,i2,j1,j2;c<k; ++c){
cin>>i1>>j1>>i2>>j2;
for(ll i=i1; i<=i2; ++i)
for(ll j=j1; j<=j2; ++j)
{
if(i%2==j%2) x++,x2--;
if(i%2!=j%2) x2++,x--;
}
}
cout<<min(x,x2);
return;
}
/*
6 8
3 3 3 3
1 2 1 2
3 4 3 4
5 5 5 5
4 3 4 3
4 4 4 4
2 1 2 1
3 6 3 6*/
int main() {
//fre_open();
IZhO_SILVER;
ll tt=1;
//cin>>tt;
while(tt--) solve();
}
Compilation message
chessboard.cpp: In function 'void solve()':
chessboard.cpp:105:8: error: redeclaration of 'll x'
105 | ll x=n*n/2;
| ^
chessboard.cpp:39:8: note: 'll x' previously declared here
39 | ll x=n*n/2;
| ^
chessboard.cpp:106:5: error: redeclaration of 'll x2'
106 | ll x2=x+1;
| ^~
chessboard.cpp:40:5: note: 'll x2' previously declared here
40 | ll x2=x+1;
| ^~
chessboard.cpp: In function 'void fre_open()':
chessboard.cpp:27:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
27 | void fre_open(){freopen("file.in","r",stdin);freopen("file.out","w",stdout);}
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~
chessboard.cpp:27:53: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
27 | void fre_open(){freopen("file.in","r",stdin);freopen("file.out","w",stdout);}
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
