Submission #464671

#	Time	Username	Problem	Language	Result	Execution time	Memory
464671		Hamed5001	Strah (COCI18_strah)	C++14	0 / 110	1079 ms	55548 KiB

strah

#include <bits/stdc++.h>

using namespace std;
typedef long long ll;

/*
	dp[i][j] = potential value in range (i, j) -> (N, M);
	dp[i][j] = dp[i+1][j] + dp[i][j+1] - dp[i+1][j+1] + (sum())
*/

const int mxN = 2e3+10;
int N, M;
char land[mxN][mxN]; 
int cum[mxN][mxN];

int query(int r1, int c1, int r2, int c2) {
	return cum[r2][c2] + cum[r1-1][c1-1] - cum[r2][c1-1] - cum[r1-1][c2];
}

bool ok(int i, int j, int ii, int mid) {
	return query(i, j, ii, mid) == 0;
}

int maxLen(int i, int ii, int j) {
	int l = 1, r = M, mid;

	while(l < r) {
		mid = (l + r + 1) >> 1;
		if (ok(i, j, ii, mid)) l = mid;
		else r = mid - 1;
	}

	return l - j + 1;
}

ll calc(int i, int j) {
	ll ret = 0;
	if (land[i][j] == '#')
		return ret;
	for (int ii = i; ii <= N && land[ii][j] != '#'; ii++) {
		ll len = maxLen(i, ii, j);
		ret += (len*(len+1)/2) * (ii-i+1);
	}

	return ret;
}

void solve() {
	cin >> N >> M;
	for (int i = 1; i <= N; i++) {
		for (int j = 1; j <= M; j++) {
			cin >> land[i][j];
			cum[i][j] += ((land[i][j] == '#') + cum[i-1][j] + cum[i][j-1] - cum[i-1][j-1]);
		}
	}

	vector<vector<ll>> dp(mxN, vector<ll>(mxN, 0));
	dp[N][M] = (land[N][M] != '#');

	for (int i = N; i; i--) {
		for (int j = M; j; j--) {
			dp[i][j] = dp[i+1][j] + dp[i][j+1] - dp[i+1][j+1] + calc(i, j);
		}
	}

	cout << dp[1][1];
}

int main() {
	ios_base::sync_with_stdio(false);
	cin.tie(0);
	solve();
}

• Subtask 1: 0 / 11
• Subtask 2: 0 / 11
• Subtask 3: 0 / 11
• Subtask 4: 0 / 11
• Subtask 5: 0 / 11
• Subtask 6: 0 / 11
• Subtask 7: 0 / 11
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• Subtask 10: 0 / 11