Submission #1288303

#	Time	Username	Problem	Language	Result	Execution time	Memory
1288303		Faisal_Saqib	The Kingdom of JOIOI (JOI17_joioi)	C++20	60 / 100	4103 ms	301872 KiB

joioi

/* 
    VENI VIDI VICI
*/

// #pragma GCC optimize("Ofast","unroll-all-loops","fast-math","no-stack-protector","give-no-*****")
#include <bits/stdc++.h>
// #include <iostream>
// #include <vector>
// #include <algorithm>
// #include <set>
// #include <map>

using namespace std;
#define fi first
#define se second
#define pb push_back
#define all(x) x.begin(),x.end()
#define rall(x) x.rbegin(),x.rend()

#define rep(i,x, n) for (int i = (x); i < (n); ++i)
#define repr(i,x, n) for (int i = (n) - 1; i >= (x); --i)
mt19937 RNG(chrono::steady_clock::now().time_since_epoch().count());  
// #define sum accumulate

//using i128 = __int128;
using ll = long long;
using ull = unsigned long long;
using ld = long double;
using str = string;
using pi = pair<int, int>;
using pl = pair<ll, ll>;

using vi = vector<int>;
using vl = vector<ll>;
using vpi = vector<pair<int, int>>;
using vvi = vector<vi>;
using sll = set<ll>;

template<class T>
istream& operator>>(istream& is, vector<T>& v) {
    for(auto &i:v) is>>i;
    return is;
}
template<class T1,class T2>
istream& operator>>(istream& is, pair<T1,T2>& p) {
    is>>p.fi>>p.se;
    return is;
}
template<class T>
ostream& operator<<(ostream& os, const vector<T>& v) {
    for(const auto &i:v) os<<i<<' ';
    return os;
}
template<class T1,class T2>
ostream& operator<<(ostream& os, const pair<T1,T2>& p) {
    os<<p.fi<<' '<<p.se; return os;
}
void pyn(bool x)
{
    cout<<(x?"YES":"NO")<<endl;
}
void pYN(bool x)
{
    cout<<(x?"Yes":"No")<<endl;
}
void pAB(bool x)
{
    cout<<(x?"Alice":"Bob")<<endl;
}
ll powmod(ll a,ll b,ll modulo)
{
  if(b==0){
    return 1;
  }
  ll temp=powmod(a,b/2,modulo);
  if(b%2==0){
    return (temp*temp)%modulo;
  }
  else{
    return (a*((temp*temp)%modulo))%modulo;
  }
}
bool Prime(ll n){
    for (ll i = 2; i*i <= n; i++)
        if (n % i == 0)
            return false;
    return (n>1);
}
void readIO() {
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
}

void solve();

int main() {
    ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);

    // readIO();

    int uwu=1;

    // cin>>uwu;

    for(int tc=1;tc<=uwu;tc++) {
        // cout<<"Case #"<<tc<<": ";
        solve();
    }
    return 0;
}
const int N=2e3+1;
int g[N][N],n,m,col[N],spf[N][N];
pair<int,int> pre[N][N],suf[N][N];
int getval()
{
  vector<vector<int>> ord(n*m);
  for(int i=0;i<n;i++)
  {
    col[i]=0;
    for(int j=0;j<m;j++)
    {
      ord[i*m+j]={g[i][j],i,j};
      pre[i][j]={g[i][j],g[i][j]};
      if(j)
      {
        pre[i][j].first=min(pre[i][j].first,pre[i][j-1].first);
        pre[i][j].second=max(pre[i][j].second,pre[i][j-1].second);
      }
    }
    for(int j=m-1;j>=0;j--)
    {
      suf[i][j]={g[i][j],g[i][j]};
      if(j<m-1)
      {
        suf[i][j].first=min(suf[i][j].first,suf[i][j+1].first);
        suf[i][j].second=max(suf[i][j].second,suf[i][j+1].second);
      }      
    }
  }
  sort(all(ord));
    int ans=2e9;
    for(auto tlp:ord)
    // for(int i=0;i<n;i++)
    {
      int i=tlp[1],j=tlp[2];
        { // fix  this as maximum
          
            for(int r=0;r<n;r++)
            {
                for(;(r==0 and col[r]<m) or (r>0 and col[r]<m and col[r]<col[r-1]);)
                {
                     if(g[r][col[r]]<=g[i][j])
                    {
                      col[r]++;
                    }
                    else
                    {
                      break;     
                    }
                }
            }
            if(col[i]>j)
            {
              int mx=-2e9,mi=2e9;
              int mx2=-2e9,mi2=2e9;
              int mip=m;
              for(int r=0;r<n;r++){
                // cout<<col[r]<<' ';
                // if(mip<col[r])exit(-1);
                mip=min(mip,col[r]);
                if(mip>0)
                {
                  mx=max(mx,pre[r][mip-1].second);
                  mi=min(mi,pre[r][mip-1].first);
                }
                if(mip<m)
                {
                  mx2=max(mx2,suf[r][mip].second);
                  mi2=min(mi2,suf[r][mip].first);                  
                }
              }
              // cout<<endl;
              if(mx!=-2e9 and mx2!=-2e9){                ans=min(ans,max(mx2-mi2,mx-mi));}
            }
        }
        // hv[i][j]=1;
    }
    return ans;
}
void rotate()
{
  for(int i=0;i<n;i++)
  {
    for(int j=0;j<m;j++)
    {
      spf[i][j]=g[i][j];
    }
  }
  swap(n,m);
  for(int i=0;i<n;i++)
  {
    for(int j=0;j<m;j++)
    {
      g[i][j]=spf[j][i];
    }
  }
  for(int i=0;i<n;i++)
  {
    reverse(g[i],g[i]+m);
  }
}
void solve()
{
    cin>>n>>m;
    for(int i=0;i<n;i++)
    {
        for(int j=0;j<m;j++)
        {
            cin>>g[i][j];
        }
    }
    int cur=2e9;
    for(int i=0;i<4;i++)
    {
      rotate();
      cur=min(cur,getval());
    }
    cout<<cur<<endl;
}

Compilation message (stderr)

joioi.cpp: In function 'void readIO()':
joioi.cpp:90:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   90 |     freopen("input.txt", "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
joioi.cpp:91:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   91 |     freopen("output.txt", "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 15 / 15
• Subtask 2: 45 / 45
• Subtask 3: 0 / 40