제출 #481370

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
481370		Lobo	The Kingdom of JOIOI (JOI17_joioi)	C++17	100 / 100	1327 ms	25684 KiB

joioi

#include <bits/stdc++.h>
 
using namespace std;

const long long INFll = (long long) 1e18 + 10;
const int INFii = (int) 1e9 + 10;
typedef long long ll;
typedef int ii;
typedef long double dbl;
#define endl '\n'
#define sc second
#define fr first
#define mp make_pair
#define pb push_back
#define all(x) x.begin(), x.end()

#define maxn 2002

ii n, m, a[maxn][maxn];
pair<ii,ii> p[maxn];

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

    //freopen("in.in", "r", stdin);
    //freopen("out.out", "w", stdout);

    cin >> n >> m;

    ii mn = INFii;
    ii mx = 0;

    for(ii i = 1; i <= n; i++) {
        for(ii j = 1; j <= m; j++) {
            cin >> a[i][j];
            mn = min(mn,a[i][j]);
            mx = max(mx,a[i][j]);
        }
    }

    if(mn == mx) {
        cout << 0 << endl;
        return 0;
    }

    // com minimo na esquerda:

    ii l = 0;
    ii r = 1e9+1;
    ii ans1;

    while(l <= r) {
        ii mid = (l+r)/2;
        for(ii i = 1; i <= n; i++) {
            p[i].fr = 0;
            p[i].sc = m+1;
        }

        
        for(ii i = 1; i <= n; i++) {
            for(ii j = 1; j <= m; j++) {
                if(abs(a[i][j]-mn) > mid) {
                    p[i].sc = min(p[i].sc,j-1);
                }

                if(abs(a[i][j]-mx) > mid) {
                    p[i].fr = max(p[i].fr,j);
                }
            }
        }

        //ver se ta crescente/decrescente
        ii actc = 0; bool okc = 1;
        ii actd = m+1; bool okd = 1;

        for(ii i = 1; i <= n; i++) {
            actc = max(actc,p[i].fr);
            if(actc > p[i].sc || p[i].fr > p[i].sc) okc = 0;

            actd = min(actd,p[i].sc);
            if(actd < p[i].fr || p[i].fr > p[i].sc) okd = 0;
        }

        if(okc || okd) {
            //se deu bom com esse (l+r)/2 quero abaixar o (l+r)/2
            ans1 = mid;
            r = mid-1;
        }
        else {
            l = mid+1;
        }
    }

    //com mx na esquerda

    l = 0;
    r = 1e9+1;
    ii ans2;


    while(l <= r) {
        ii mid = (l+r)/2;
        for(ii i = 1; i <= n; i++) {
            p[i].fr = 0;
            p[i].sc = m+1;
        }

        
        for(ii i = 1; i <= n; i++) {
            for(ii j = 1; j <= m; j++) {
                if(abs(a[i][j]-mn) > mid) {
                    p[i].fr = max(p[i].fr,j);
                }

                if(abs(a[i][j]-mx) > mid) {
                    p[i].sc = min(p[i].sc,j-1);
                }
            }
        }

        //ver se ta crescente/decrescente
        ii actc = 0; bool okc = 1;
        ii actd = m+1; bool okd = 1;

        for(ii i = 1; i <= n; i++) {
            actc = max(actc,p[i].fr);
            if(actc > p[i].sc || p[i].fr > p[i].sc) okc = 0;

            actd = min(actd,p[i].sc);
            if(actd < p[i].fr || p[i].fr > p[i].sc) okd = 0;
        }

        if(okc || okd) {
            //se deu bom com esse (l+r)/2 quero abaixar o (l+r)/2
            ans2 = mid;
            r = mid-1;
        }
        else {
            l = mid+1;
        }
    }

    cout << min(ans1,ans2) << endl;

}

컴파일 시 표준 에러 (stderr) 메시지

joioi.cpp: In function 'int main()':
joioi.cpp:98:8: warning: 'ans2' may be used uninitialized in this function [-Wmaybe-uninitialized]
   98 |     ii ans2;
      |        ^~~~
joioi.cpp:50:8: warning: 'ans1' may be used uninitialized in this function [-Wmaybe-uninitialized]
   50 |     ii ans1;
      |        ^~~~

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