Submission #152634

#	Time	Username	Problem	Language	Result	Execution time	Memory
152634		karma	The Kingdom of JOIOI (JOI17_joioi)	C++14	0 / 100	2 ms	504 KiB

joioi

#include<bits/stdc++.h>
#define pb      emplace_back
#define mp      make_pair
#define fi      first
#define se      second
#define ll      long long

using namespace std;

const int N = int(2e3) + 7;
const int inf = int(1e9) + 7;

int n, m, a[N][N], mn, mx, res;
int lefMin[N], lefMax[N], rigMax[N], rigMin[N];

bool Check(int dif) {
     int lim = mn + dif;
     int Mx = 0, Mn = inf;
     for(int j = 0; j < m; ++j) {
         if(a[0][j] > lim) {
             Mx = max(Mx, rigMax[j]);
             Mn = min(Mn, rigMin[j]);
             if(Mx - Mn <= dif) return 1;
             Mx = lefMax[j], Mn = lefMin[j]; continue;
         }
         bool divided = 0;
         for(int i = 0; i < n; ++i) {
            if(a[i][j] <= lim && !divided) continue;
            Mx = max(Mx, a[i][j]), Mn = min(Mn, a[i][j]);
            divided = 1;
         }
     }
    return Mx - Mn <= dif;
}

void Solve() {
     fill_n(rigMax, m + 1, 0);
     fill_n(rigMin, m + 1, inf);
     fill_n(lefMax, m + 1, 0);
     fill_n(lefMin, m + 1, inf);
     for(int i = n - 1; i >= 0; --i) {
         for(int j = 0; j < m; ++j) {
            if(j) {
                lefMax[j] = max({lefMax[j], lefMax[j - 1], a[i][j]});
                lefMin[j] = min({lefMax[j], lefMin[j - 1], a[i][j]});
            } else {
                lefMax[j] = max(lefMax[j], a[i][j]);
                lefMin[j] = min(lefMin[j], a[i][j]);
            }
         }
         for(int j = m - 1; j >= 0; --j) {
            if(j + 1 < m) {
                rigMax[j] = max({rigMax[j], rigMax[j + 1], a[i][j]});
                rigMin[j] = min({rigMin[j], rigMin[j + 1], a[i][j]});
            } else {
                rigMax[j] = max(rigMax[j], a[i][j]);
                rigMin[j] = min(rigMin[j], a[i][j]);
            }
         }
     }
     int low, high, mid;
     low = 0, high = mx - mn;
     while(low <= high) {
         mid = (low + high) >> 1;
         if(Check(mid)) high = mid - 1;
         else low = mid + 1;
     }
     res = min(res, low);
}

int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0), cout.tie(0);
    if(fopen("test.inp", "r")) {
        freopen("test.inp", "r", stdin);
        freopen("test.out", "w", stdout);
    }
    cin >> n >> m; mn = inf, mx = 0;
    for(int i = 0; i < n; ++i) {
        for(int j = 0; j < m; ++j) {
           cin >> a[i][j];
           mn = min(mn, a[i][j]);
           mx = max(mx, a[i][j]);
        }
    }
    res = mx - mn;
    Solve();
    for(int j = 0; j < m; ++j) {
        for(int i = 0; n - 1 - i > i; ++i) {
            swap(a[i][j], a[n - 1 - i][j]);
        }
    }
    Solve();
    cout << res;
}

Compilation message (stderr)

joioi.cpp: In function 'int main()':
joioi.cpp:75:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
         freopen("test.inp", "r", stdin);
         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
joioi.cpp:76:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
         freopen("test.out", "w", stdout);
         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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