[2018-4-20]BNUZ套题比赛div2 CodeForces 548B Mike and Fun【补】

B. Mike and Fun
time limit per test
2 seconds
memory limit per test
256 megabytes
input
standard input
output
standard output

Mike and some bears are playing a game just for fun. Mike is the judge. All bears except Mike are standing in an n × m grid, there's exactly one bear in each cell. We denote the bear standing in column number j of row number i by (i, j). Mike's hands are on his ears (since he's the judge) and each bear standing in the grid has hands either on his mouth or his eyes.

They play for q rounds. In each round, Mike chooses a bear (i, j) and tells him to change his state i. e. if his hands are on his mouth, then he'll put his hands on his eyes or he'll put his hands on his mouth otherwise. After that, Mike wants to know the score of the bears.

Score of the bears is the maximum over all rows of number of consecutive bears with hands on their eyes in that row.

Since bears are lazy, Mike asked you for help. For each round, tell him the score of these bears after changing the state of a bear selected in that round.

Input

The first line of input contains three integers nm and q (1 ≤ n, m ≤ 500 and 1 ≤ q ≤ 5000).

The next n lines contain the grid description. There are m integers separated by spaces in each line. Each of these numbers is either 0 (for mouth) or 1 (for eyes).

The next q lines contain the information about the rounds. Each of them contains two integers i and j (1 ≤ i ≤ n and 1 ≤ j ≤ m), the row number and the column number of the bear changing his state.

Output

After each round, print the current score of the bears.

Examples
input
Copy
5 4 5
0 1 1 0
1 0 0 1
0 1 1 0
1 0 0 1
0 0 0 0
1 1
1 4
1 1
4 2
4 3
output
Copy
3
4
3
3
4

题意:给一个 n* m的矩阵,让你转换对应点的状态 然后输出的 每一行中 最大连续1的个数

题解:这里要先做一个 预处理,把每一行中连续一的 个数 记录下来,然后之后 只要计算 改变的那一行的 最大连续一的数量。

AC代码:

#include <bits/stdc++.h>

using namespace std;

int q[555][555], ans[555];

int main() {
	int n, m, k;
	cin >> n >> m >> k;
	for (int i = 1; i <= n; ++i) {
		ans[i] = 0;
		int cnt =  0;
		for (int j = 1; j <= m; ++j) {
			scanf("%d", &q[i][j]);
			if (q[i][j]) {
				cnt++;
				ans[i] = max(cnt, ans[i]);
			}
			else
				cnt = 0;
		}
	}
	int u, v;
	for (int i = 1; i <= k; ++i) {
		scanf("%d %d", &u, &v);
		q[u][v] = !q[u][v];
		ans[u] = 0;
		int cnt = 0;
		for (int j = 1; j <= m; j++) {
			if (q[u][j]) {
				cnt++;
				ans[u] = max(ans[u], cnt);
			} else
				cnt = 0;
		}
		cout << *max_element(ans+1, ans+n+1) << endl;
	}
}


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转载自blog.csdn.net/qq_40731186/article/details/80041885