Submission #118140

#	Time	Username	Problem	Language	Result	Execution time	Memory
118140		JohnTitor	The Kingdom of JOIOI (JOI17_joioi)	C++11	100 / 100	1022 ms	70616 KiB

joioi

#include <bits/stdc++.h>
using namespace std;
#define FOR(i, j, k) for(int i=(j); i<=(k); i++)
#define FFOR(i, j, k) for(int i=(j); i<(k); i++)
#define DFOR(i, j, k) for(int i=(j); i>=(k); i--)
#define bug(x) cerr<<#x<<" = "<<(x)<<'\n'
#define pb push_back
#define mp make_pair
#define bit(s, i) (((s)>>(i))&1LL)
#define mask(i) ((1LL<<(i)))
#define builtin_popcount __builtin_popcountll
#define __builtin_popcount __builtin_popcountll
using ll=long long; using ld=long double;
mt19937_64 rng(chrono::high_resolution_clock::now().time_since_epoch().count()); const ld pi=acos(0)*2;
template <typename T> inline void read(T &x){char c; bool nega=0; while((!isdigit(c=getchar()))&&(c!='-')); if(c=='-'){nega=1; c=getchar();} x=c-48; while(isdigit(c=getchar())) x=x*10+c-48; if(nega) x=-x;}
template <typename T> inline void writep(T x){if(x>9) writep(x/10); putchar(x%10+48);}
template <typename T> inline void write(T x){if(x<0){ putchar('-'); x=-x;} writep(x);}
template <typename T> inline void writeln(T x){write(x); putchar('\n');}
#define taskname "Kingdom"
int h, w;
int a[2001][2001];
int mx, mi=1e9;
int f[2001][2001];
bool check(int dist){
    FOR(i, 1, h) FOR(j, 1, w) f[i][j]=0;
    FOR(i, 1, h) FOR(j, 1, w){
        if(mx-a[i][j]<=dist) f[i][j]^=1;
        if(a[i][j]-mi<=dist) f[i][j]^=2;
        if(f[i][j]==0) return 0;
    }
    {
        bool goodlr=1;
        bool goodrl=1;
        int nowl=0;
        int nowr=w+1;
        FOR(i, 1, h){
            int l=0, r=w+1;
            DFOR(j, w, 1) if(f[i][j]==1){
                l=j;
                break;
            }
            FOR(j, 1, w) if(f[i][j]==2){
                r=j-1;
                break;
            }
//            cerr<<"a "<<i<<' '<<l<<' '<<r<<'\n';
            nowl=max(l, nowl);
            if(nowl>r){
                goodlr=0;
                if(goodrl==0) break;
            }
            nowr=min(r, nowr);
            if(nowr<l){
                goodrl=0;
                if(goodlr==0) break;
            }
        }
        if(goodrl||goodlr) return 1;
    }
    {
        bool goodlr=1;
        bool goodrl=1;
        int nowl=0;
        int nowr=w+1;
        FOR(i, 1, h){
            int l=0, r=w+1;
            DFOR(j, w, 1) if(f[i][j]==2){
                l=j;
                break;
            }
            FOR(j, 1, w) if(f[i][j]==1){
                r=j-1;
                break;
            }
//            cerr<<"b "<<i<<' '<<l<<' '<<r<<'\n';
            nowl=max(l, nowl);
            if(nowl>r){
                goodlr=0;
                if(goodrl==0) break;
            }
            nowr=min(r, nowr);
            if(nowr<l){
                goodrl=0;
                if(goodlr==0) break;
            }
        }
        if(goodrl||goodlr) return 1;
    }
    return 0;
}
int main(){
    #ifdef Aria
        if(fopen(taskname".in", "r"))
            freopen(taskname".in", "r", stdin);
    #endif // Aria
    read(h);
    read(w);
    FOR(i, 1, h) FOR(j, 1, w){
        read(a[i][j]);
        if(a[i][j]>mx) mx=a[i][j];
        if(a[i][j]<mi) mi=a[i][j];
    }
    int ans=mx-mi;
    int low=0, high=ans-1, mid;
//    bug(check(11));
//    bug(check(11));
//    bug(check(11));
//    bug(check(11));
//    bug(check(11));
    while(low<=high){
        mid=(low+high)/2;
//        bug(mid);
//        bug(check(mid));
        if(check(mid)){
            ans=mid;
            high=mid-1;
        }
        else low=mid+1;
    }
    writeln(ans);
}

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