蓝桥杯 0穿越雷区 题型：搜索模板题

0穿越雷区 - 蓝桥云课 (lanqiao.cn)、

因为要求最近距离，所以用Bfs

#include <bits/stdc++.h>
using namespace std;

typedef pair<int, int>PII;
int n;
const int N = 110;
char g[N][N];
int vis[N][N];
int dis[N][N];
PII start,	End;

int dx[] = {-1, 0, 1, 0}, dy[] = {0, 1, 0, -1};
void bfs(PII start) {
	queue<PII> q;
	q.push(start);
	vis[start.first][start.second] = 1; //标记为走过
	dis[start.first][start.second] = 0; // 原地不动就是0

	while (!q.empty()) {
		PII t = q.front();
		q.pop();

		for (int i = 0; i < 4; i++) {
			int tx = t.first + dx[i], ty = t.second + dy[i];

			if (tx < 1 || tx > n || ty < 1 || ty > n || vis[tx][ty] == 1 || g[tx][ty] == g[t.first][t.second])
				continue;


			vis[tx][ty] = 1; //标记为走过
			dis[tx][ty] = dis[t.first][t.second] + 1; //距离+1
			q.push({tx, ty});
		}
	}
}
int main() {
	cin >> n;
	for (int i = 1; i <= n; i++) {
		for (int j = 1; j <= n; j++) {
			cin >> g[i][j];
			if (g[i][j] == 'A') {
				start = {i, j};
			}
			if (g[i][j] == 'B') {
				End = {i, j};
			}
		}
	}

	bfs(start);

	if (dis[End.first][End.second])
		cout << dis[End.first][End.second] << endl;
	else
		cout << "-1" << endl;
	return 0;
}