Submission #317067

#	Time	Username	Problem	Language	Result	Execution time	Memory
317067		8e7	Maxcomp (info1cup18_maxcomp)	C++14	100 / 100	140 ms	8312 KiB

maxcomp

#include <iostream>
#include <algorithm>
#include <utility>
#include <vector>
#define ll long long
#define pii pair<int, int>
#define maxn 1005
using namespace std;
int a[maxn][maxn], val[maxn][maxn];
int n, m;
inline int ab(int a) {
	return a > 0 ? a : -a;
}
const int NINF = -1000010000;
/*
struct BIT{
	int bit[maxn][maxn];
	void init(){
		for (int i = 0;i < maxn;i++) {
			for (int j = 0;j < maxn;j++) bit[i][j] = -NINF;
		}
	}
	void modify(int x, int y, int val) {
		for (;x < maxn;x += x & (-x)) {
			for(int c = y;c < maxn;c += c & (-c)) bit[x][c] = max(bit[x][c], val);
		}
	}
	int query(int x, int y) {
		int ret = NINF;
		for (;x > 0;x -= x & (-x)) {
			for (int c = y;c > 0;c -= c & (-c)) ret = max(ret, bit[x][c]);
		}
		return ret;
	}
} bit;
*/
int main() {
	ios_base::sync_with_stdio(0);cin.tie(0);
	cin >> n >> m;
	for (int i = 0;i < n;i++) {
		for (int j = 0;j < m;j++) cin >> a[i][j];
	}
	int ans = NINF;
	for (int i = 0;i < n;i++) {
		for (int j = 0;j < m;j++) {
			val[i][j] = max(-a[i][j] + i + j, max(i ? val[i - 1][j] : NINF, j ? val[i][j - 1] : NINF));
			//cout << val[i][j] << " ";
			ans = max(ans, a[i][j] - i - j - 1 + val[i][j]);
		}
		//cout << endl;
	}
	//cout << ans << endl;
	for (int i = n - 1;i >= 0;i--) {
		for (int j = 0;j < m;j++) {
			val[i][j] = max(-a[i][j] - i + j, max(i < n - 1 ? val[i + 1][j] : NINF, j ? val[i][j - 1] : NINF));
			ans = max(ans, a[i][j] + i - j - 1 + val[i][j]);
		}
	}
	for (int i = 0;i < n;i++) {
		for (int j = m - 1;j >= 0;j--) {
			val[i][j] = max(-a[i][j] + i - j, max(i ? val[i - 1][j] : NINF, j < m - 1 ? val[i][j + 1] : NINF));
			ans = max(ans, a[i][j] - i + j - 1 + val[i][j]);
		}
	}
	for (int i = n - 1;i >= 0;i--) {
		for (int j = m - 1;j >= 0;j--) {
			val[i][j] = max(-a[i][j] - i - j, max(i < n - 1 ? val[i + 1][j] : NINF, j < m - 1 ? val[i][j + 1] : NINF));
			ans = max(ans, a[i][j] + i + j - 1 + val[i][j]);
		}
	}
	cout << ans << endl;
}
/*
1 5
2 4 5 6 3

2 3
2 4 3
5 7 5
 */

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