最大连通块问题(dfs做法)

https://blog.csdn.net/m0_62946761/article/details/129333174
第十四届蓝桥杯第三次模拟赛

第E题 最大连通块

答案:148

问题描述
  小蓝有一个 30 行 60 列的数字矩阵,矩阵中的每个数都是 0 或 1 。

110010000011111110101001001001101010111011011011101001111110
  010000000001010001101100000010010110001111100010101100011110
  001011101000100011111111111010000010010101010111001000010100
  101100001101011101101011011001000110111111010000000110110000
  010101100100010000111000100111100110001110111101010011001011
  010011011010011110111101111001001001010111110001101000100011
  101001011000110100001101011000000110110110100100110111101011
  101111000000101000111001100010110000100110001001000101011001
  001110111010001011110000001111100001010101001110011010101110
  001010101000110001011111001010111111100110000011011111101010
  011111100011001110100101001011110011000101011000100111001011
  011010001101011110011011111010111110010100101000110111010110
  001110000111100100101110001011101010001100010111110111011011
  111100001000001100010110101100111001001111100100110000001101
  001110010000000111011110000011000010101000111000000110101101
  100100011101011111001101001010011111110010111101000010000111
  110010100110101100001101111101010011000110101100000110001010
  110101101100001110000100010001001010100010110100100001000011
  100100000100001101010101001101000101101000000101111110001010
  101101011010101000111110110000110100000010011111111100110010
  101111000100000100011000010001011111001010010001010110001010
  001010001110101010000100010011101001010101101101010111100101
  001111110000101100010111111100000100101010000001011101100001
  101011110010000010010110000100001010011111100011011000110010
  011110010100011101100101111101000001011100001011010001110011
  000101000101000010010010110111000010101111001101100110011100
  100011100110011111000110011001111100001110110111001001000111
  111011000110001000110111011001011110010010010110101000011111
  011110011110110110011011001011010000100100101010110000010011
  010011110011100101010101111010001001001111101111101110011101

如果从一个标为 1 的位置可以通过上下左右走到另一个标为 1 的位置,则称两个位置连通。与某一个标为 1 的位置连通的所有位置(包括自己)组成一个连通分块。
  请问矩阵中最大的连通分块有多大?
答案提交
  这是一道结果填空的题,你只需要算出结果后提交即可。本题的结果为一个整数,在提交答案时只填写这个整数,填写多余的内容将无法得分。

#include 

using namespace std;

int g[35][65];
int n = 30, m = 60;

void dfs(int x, int y) {
	g[x][y] = 0;
	int dx[4] = {0, 1, 0, -1}, dy[4] = {1, 0, -1, 0};
	for (int i = 0; i < 4; i++) {
		x += dx[i], y += dy[i];
		if (x >= 0 && x <= n && y >= 0 && y <= m && g[x][y] == 1) {
			dfs(x, y);
		}
	}
	return;
}

int main() {
	for (int i = 0; i < n; i++) {
		for (int j = 0; j < m; j++) {
			char c;
			cin >> c;
			g[i][j] = c - '0';
		}
	}
	int ans = 0;
	for (int i = 0; i < n; i++) {
		for (int j = 0; j < m; j++) {
			if (g[i][j] == 1) {
				dfs(i, j);
				ans++;
			}
		}
	}
	cout << ans << endl;
	return 0;
}

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