Submission #752825

#	Time	Username	Problem	Language	Result	Execution time	Memory
752825		guagua0407	The Kingdom of JOIOI (JOI17_joioi)	C++17	100 / 100	1391 ms	102004 KiB

joioi

//#pragma GCC optimize("O3")
#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define int ll
#define pii pair<int,int>
#define f first
#define s second
#define all(x) x.begin(),x.end()
#define _ ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);

void setIO(string s) {
    freopen((s + ".in").c_str(), "r", stdin);
    freopen((s + ".out").c_str(), "w", stdout);
}

const int mxn=2e3+5;
int a[mxn][mxn];
vector<int> vec;
int n,m;
int mn=1e9;
int mx=0;

bool check(int mid){
    int best=m;
    int sir[n];
    for(int i=0;i<n;i++){
        int j=0;
        while(j<best and a[i][j]<=mn+mid) j++;
        best=j;
        sir[i]=j;
    }
    int mnn=1e9;
    int mxx=0;
    for(int i=0;i<n;i++){
        for(int j=sir[i];j<m;j++){
            mnn=min(mnn,a[i][j]);
            mxx=max(mxx,a[i][j]);
        }
    }
    return (mxx-mnn)<=mid;
}

bool ok(int mid){
    if(check(mid)) return true;
    reverse(a,a+n);
    if(check(mid)) return true;
    for(int i=0;i<n;i++){
        reverse(a[i],a[i]+m);
    }
    if(check(mid)) return true;
    reverse(a,a+n);
    if(check(mid)) return true;
    return false;
}

signed main() {_
    cin>>n>>m;
    for(int i=0;i<n;i++){
        for(int j=0;j<m;j++){
            cin>>a[i][j];
            vec.push_back(a[i][j]);
            mx=max(mx,a[i][j]);
            mn=min(mn,a[i][j]);
        }
    }
    sort(all(vec));
    int l=0,r=mx-mn;
    while(l<r){
        int mid=(l+r)/2;
        if(ok(mid)){
            r=mid;
        }
        else{
            l=mid+1;
        }
    }
    cout<<l<<'\n';
    return 0;
}
//maybe its multiset not set

Compilation message (stderr)

joioi.cpp: In function 'void setIO(std::string)':
joioi.cpp:13:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   13 |     freopen((s + ".in").c_str(), "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
joioi.cpp:14:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   14 |     freopen((s + ".out").c_str(), "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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