2023年码题杯E题- 地狱尖兵 题型：搜索

码题集OJ-地狱尖兵 (matiji.net)

#include<bits/stdc++.h> 
using namespace std;
const int N = 510;
char g[N][N];
typedef pair<int, int> PII;
#define x first
#define y second
int dist1[N][N];
int dist2[N][N];
int cnt1, cnt2;
int n, m;

int dx[] = {-1, 0, 1, 0}, dy[] = {0, 1, 0, -1};
void bfs2(int tx,int ty) {
	queue<PII> q;
	q.push({tx,ty});
	dist2[tx][ty] = 0;

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

		for (int i = 0; i < 4; i++) {
			int x = t.x + dx[i], y = t.y + dy[i];

			if (x >= 0 && x < n && y >= 0 && y < m && dist2[x][y] == -1 && g[x][y] != '#') {
				dist2[x][y] = dist2[t.x][t.y] + 1;
				q.push({x, y});
				if (g[x][y] == 'E') {
					cnt2 += dist2[x][y];
					return;
				}
			}
		}
	}
}
void bfs1(int x,int y) {
	queue<PII> q;
	q.push({x,y});
	dist1[x][y] = 0;

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

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

			if (tx >= 0 && tx < n && ty >= 0 && ty < m && dist1[tx][ty] == -1 && g[tx][ty] != '#' && g[tx][ty] != 'E') {

				dist1[tx][ty] = dist1[t.x][t.y] + 1;
				q.push({tx, ty});

				if (g[tx][ty] == 'K') {
					cnt1 = dist1[tx][ty];
					bfs2(tx, ty);
					return;
				}
			}
		}
	}
}

int main() {
	int t;
	cin >> t;
	while (t--) {
		memset(dist1, -1, sizeof dist1);
		memset(dist2, -1, sizeof dist2);
		cnt1 = 0, cnt2 = 0;
		cin >> n >> m;
		for (int i = 0; i < n; i++)
			for (int j = 0; j < m; j++)
				cin >> g[i][j];

		int x,y;
		for (int i = 0; i < n; i++)
			for (int j = 0; j < m; j++)
				if (g[i][j] == 'P')
				x=i,y=j;

		bfs1(x,y);

		if (cnt1 && cnt2)
			cout << cnt1 + cnt2 << endl;
		else
			cout << "No solution" << endl;
	}
	return 0;
}