Submission #887484

#	Time	Username	Problem	Language	Result	Execution time	Memory
887484		hafo	The Kingdom of JOIOI (JOI17_joioi)	C++14	100 / 100	1166 ms	51796 KiB

joioi

#include <bits/stdc++.h>
#define ll long long
#define ull unsigned ll
#define pb push_back
#define pa pair<int, int>
#define pall pair<ll, int>
#define fi first
#define se second
#define TASK "test"
#define Size(x) (int) x.size()
#define all(x) x.begin(), x.end()
using namespace std;

template<typename T1, typename T2> bool mini (T1 &a, T2 b) {if(a > b) a = b; else return 0; return 1;}
template<typename T1, typename T2> bool maxi (T1 &a, T2 b) {if(a < b) a = b; else return 0; return 1;}

const int MOD = 1e9 + 7;
const int LOG = 21;
const int maxn = 2e3 + 7;
const ll oo = 1e9 + 69;

int n, m, a[maxn][maxn], mx, mn, b[maxn][maxn];

bool ok(int d) { 
    int last = 0;
    for(int i = 1; i <= n; i++) {
        int r = m;
        for(int j = m; j >= 1; j--) {
            if(a[i][j] >= mx - d) r--;
            else break;
        }
        maxi(last, r);
        for(int j = 1; j <= last; j++) {
            if(a[i][j] > mn + d) return 0;
        }

    }
    return 1;
}

void flip() {
    for(int i = 1; i <= n; i++) {
        for(int j = 1; j <= m; j++) {
            b[j][n - i + 1] = a[i][j];
        }
    }

    swap(n, m);
    for(int i = 1; i <= n; i++) {
        for(int j = 1; j <= m; j++) a[i][j] = b[i][j];
    }
}

bool check(int d) {
    int ans = 0;
    for(int i = 0; i < 4; i++) {
        if(ok(d)) return 1;
        flip();
    }
    return 0;
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

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

    cin>>n>>m;
    mx = 0;
    mn = oo;
    for(int i = 1; i <= n; i++) {
        for(int j = 1; j <= m; j++) {
            cin>>a[i][j];
            maxi(mx, a[i][j]);
            mini(mn, a[i][j]);
        }
    }
        
    int l = 0, r = mx - mn, mid, res;
    while(l <= r) {
        mid = l + r >> 1;
        if(check(mid)) {
            res = mid;
            r = mid - 1;
        } else l = mid + 1;
    }    
    cout<<res;
    return 0;
}

Compilation message (stderr)

joioi.cpp: In function 'bool check(int)':
joioi.cpp:55:9: warning: unused variable 'ans' [-Wunused-variable]
   55 |     int ans = 0;
      |         ^~~
joioi.cpp: In function 'int main()':
joioi.cpp:83:17: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   83 |         mid = l + r >> 1;
      |               ~~^~~
joioi.cpp:89:11: warning: 'res' may be used uninitialized in this function [-Wmaybe-uninitialized]
   89 |     cout<<res;
      |           ^~~

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