hdu1180 诡异的楼梯--BFS

来源：互联网发布：如何劫持域名编辑：程序博客网时间：2024/06/09 21:40

原题链接：http://acm.hdu.edu.cn/showproblem.php?pid=1180

需要注意这句话：Harry每秒只能停留在'.'或'S'和'T'所标记的格子内.

#define _CRT_SECURE_NO_DEPRECATE #define _CRT_SECURE_Cy1_OVERLOAD_STANDARD_NAMES 1 #include <stdio.h>#include <algorithm>#include <iostream>#include <queue>#include <string.h>using namespace std;const int N = 50;const int INF = 1000000;char Map[N][N];bool vis[N][N];int n, m;int dir[4][2] = { { 1, 0 },{ -1, 0 },{ 0, 1 },{ 0, -1 } };struct node{int x, y;int step;friend bool operator < (const node &a, const node &b){return a.step > b.step;}};node st;bool check(int x, int y){if (x >= 0 && x < n && y >= 0 && y < m && !vis[x][y] && Map[x][y] != '*') return true;else return false;}int bfs(int x, int y){char c;priority_queue <node> q;node s_pos;s_pos.x = x;s_pos.y = y;s_pos.step = 0;vis[s_pos.x][s_pos.y] = 1;q.push(s_pos);while (!q.empty()){node tmp = q.top();q.pop();for (int i = 0; i < 4; i++){node tmp2;tmp2 = tmp;tmp2.x += dir[i][0];tmp2.y += dir[i][1];tmp2.step += 1;if (check(tmp2.x, tmp2.y) && (Map[tmp2.x][tmp2.y] == '-' || Map[tmp2.x][tmp2.y] == '|')){if (tmp2.step % 2 == 1){if (Map[tmp2.x][tmp2.y] == '-') c = '|';else if (Map[tmp2.x][tmp2.y] == '|') c = '-';}else c = Map[tmp2.x][tmp2.y];tmp2.x += dir[i][0];//????tmp2.y += dir[i][1];if ((c == '-' && (dir[i][1] == -1 || dir[i][1] == 1)) || (c == '|' && (dir[i][0] == -1 || dir[i][0] == 1)))tmp2.step += 1;}if (check(tmp2.x, tmp2.y)){if (Map[tmp2.x][tmp2.y] == 'T') return tmp2.step;vis[tmp2.x][tmp2.y] = 1;q.push(tmp2);}}}return -1;}int main(){while (~scanf("%d%d", &n, &m)){for (int i = 0; i < n; i++)for (int j = 0; j < m; j++){cin >> Map[i][j];if (Map[i][j] == 'S'){st.x = i;st.y = j;}}memset(vis, 0, sizeof(vis));int ans = bfs(st.x, st.y);printf("%d\n", ans);}return 0;}

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