HDU 1180 诡异楼梯 bfs

#include <iostream>#include <queue>using namespace std;const int N = 25;struct node{int x, y, time;};char a[N][N];int mark[N][N];int x1, y11, x2, y2;int dis[4][2] = {{1,0}, {-1, 0}, {0, 1}, {0, -1}};void bfs(){queue<node> q;node s1, s2;s1.x = x1;s1.y = y11;s1.time = 0;q.push(s1);int i;memset(mark, 0, sizeof(mark));mark[s1.x][s1.y] = 1;while(!q.empty()){s1 = q.front();q.pop();if(s1.x == x2 && s1.y == y2){printf("%d\n", s1.time);return;}for(i = 0; i < 4; i++){s2.x = s1.x + dis[i][0];s2.y = s1.y + dis[i][1];if(mark[s2.x][s2.y] == 0 && a[s2.x][s2.y] != '*'){if(a[s2.x][s2.y] == '.'){s2.time = s1.time + 1;q.push(s2);mark[s2.x][s2.y] = 1;}if(a[s2.x][s2.y] == '-' && (s1.time & 1) == 0 || a[s2.x][s2.y]  == '|' && s1.time & 1){if(s2.x == s1.x){s2.y = s2.y + s2.y - s1.y;s2.time = s1.time + 1;if(a[s2.x][s2.y] != '*' && mark[s2.x][s2.y] == 0){q.push(s2);mark[s2.x][s2.y] = 1;mark[s1.x][s1.y] = 1;}}else{s2.x = s2.x + s2.x - s1.x;s2.time = s1.time + 1;q.push(s2);}}if(a[s2.x][s2.y] == '|' && (s1.time & 1) == 0 || a[s2.x][s2.y] == '-' && s1.time & 1){if(s2.y == s1.y){s2.x = s2.x + s2.x - s1.x;s2.time = s1.time + 1;if(a[s2.x][s2.y] != '*' && mark[s2.x][s2.y] == 0){q.push(s2);mark[s2.x][s2.y] = 1;mark[s1.x][s1.y] = 1;}}else{s2.y = s2.y + s2.y - s1.y;s2.time = s1.time + 2;q.push(s2);}}}}}}int main(){int n, m, i, j;while(cin >> n >>m){memset(a, '*', sizeof(a));for(i = 1; i <= n; i++){for(j = 1; j <= m; j++){cin >> a[i][j];if(a[i][j] == 'S'){x1 = i;y11 = j;}else if(a[i][j] == 'T'){x2 = i;y2 = j;a[i][j] = '.';}}getchar();}bfs();}return 0;}