Submission #61861

#	Time	Username	Problem	Language	Result	Execution time	Memory
61861		Benq	Maxcomp (info1cup18_maxcomp)	C++11	100 / 100	244 ms	76012 KiB

maxcomp

#include <bits/stdc++.h>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/assoc_container.hpp>

using namespace std;
using namespace __gnu_pbds;
 
typedef long long ll;
typedef long double ld;
typedef complex<ld> cd;

typedef pair<int, int> pi;
typedef pair<ll,ll> pl;
typedef pair<ld,ld> pd;

typedef vector<int> vi;
typedef vector<ld> vd;
typedef vector<ll> vl;
typedef vector<pi> vpi;
typedef vector<pl> vpl;
typedef vector<cd> vcd;

template <class T> using Tree = tree<T, null_type, less<T>, rb_tree_tag,tree_order_statistics_node_update>;

#define FOR(i, a, b) for (int i=a; i<(b); i++)
#define F0R(i, a) for (int i=0; i<(a); i++)
#define FORd(i,a,b) for (int i = (b)-1; i >= a; i--)
#define F0Rd(i,a) for (int i = (a)-1; i >= 0; i--)

#define sz(x) (int)(x).size()
#define mp make_pair
#define pb push_back
#define f first
#define s second
#define lb lower_bound
#define ub upper_bound
#define all(x) x.begin(), x.end()

const int MOD = 1000000007;
const ll INF = 1e18;
const int MX = 100001;

int N,M;
ll ans = -INF, A[1000][1000], bes[1000][1000];

ll solve() {
    ll ret = -INF;
    F0Rd(i,N) F0Rd(j,M) {
        bes[i][j] = -INF;
        if (i < N-1) bes[i][j] = max(bes[i][j],bes[i+1][j]);
        if (j < M-1) bes[i][j] = max(bes[i][j],bes[i][j+1]);
        bes[i][j] = max(bes[i][j],A[i][j]-i-j);
        ret = max(ret,bes[i][j]-A[i][j]+i+j-1);
    }
    return ret;
}

int main() {
    ios_base::sync_with_stdio(0); cin.tie(0);
    cin >> N >> M;
    F0R(i,N) F0R(j,M) cin >> A[i][j];
    ans = solve();
    F0R(i,N) for (int j = 0; j < M-1-j; ++j) swap(A[i][j],A[i][M-1-j]);
    ans = max(ans,solve());
    for (int i = 0; i < N-1-i; ++i) F0R(j,M) swap(A[i][j],A[N-1-i][j]);
    ans = max(ans,solve());
    F0R(i,N) for (int j = 0; j < M-1-j; ++j) swap(A[i][j],A[i][M-1-j]);
    ans = max(ans,solve());
    cout << ans;
}

/* Look for:
* the exact constraints (multiple sets are too slow for n=10^6 :( ) 
* special cases (n=1?)
* overflow (ll vs int?)
* array bounds
*/

• Subtask 1: 15 / 15
• Subtask 2: 15 / 15
• Subtask 3: 30 / 30
• Subtask 4: 40 / 40