hdu 1026 Ignatius and the Princess I

原题链接：http://acm.hdu.edu.cn/showproblem.php?pid=1026
bfs+路径记录。。

#include<algorithm>#include<iostream>#include<cstdlib>#include<cstring>#include<cstdio>#include<vector>#include<queue>#include<map>using std::cin;using std::cout;using std::endl;using std::find;using std::sort;using std::pair;using std::vector;using std::multimap;using std::priority_queue;#define pb(e) push_back(e)#define sz(c) (int)(c).size()#define mp(a, b) make_pair(a, b)#define all(c) (c).begin(), (c).end()#define iter(c) decltype((c).begin())#define cls(arr,val) memset(arr,val,sizeof(arr))#define cpresent(c, e) (find(all(c), (e)) != (c).end())#define rep(i, n) for (int i = 0; i < (int)(n); i++)#define tr(c, i) for (iter(c) i = (c).begin(); i != (c).end(); ++i)const int Max_N = 110;const int Mod = 110;typedef unsigned long long ull;const int dx[] = { 0, 0, -1, 1 }, dy[] = { -1, 1, 0, 0 };bool vis[Max_N][Max_N];char maze[Max_N][Max_N];int N, M, res, fa[Max_N][Max_N], dir[Max_N][Max_N];namespace work {    struct Node {        int x, y, s;        Node(int i = 0, int j = 0, int k = 0) :x(i), y(j), s(k) {}        inline bool operator<(const Node &a) const {            return s > a.s;        }    };    void bfs() {        cls(vis, false), cls(fa, 0), cls(dir, 0);        priority_queue<Node> q;        q.push(Node());        while (!q.empty()) {            Node t = q.top(); q.pop();            if (t.x == N - 1 && t.y == M - 1) { res = t.s; return; }            rep(i, 4) {                int nx = t.x + dx[i], ny = t.y + dy[i];                char &ch = maze[nx][ny];                if (nx < 0 || nx >= N || ny < 0 || ny >= M) continue;                if (ch == 'X' || vis[nx][ny]) continue;                if ('0' <= ch && ch <= '9') q.push(Node(nx, ny, t.s + 1 + ch - '0'));                else q.push(Node(nx, ny, t.s + 1));                vis[nx][ny] = true;                fa[nx][ny] = t.x * Mod + t.y;                dir[nx][ny] = i;            }        }        res = -1;    }    void show_path(int x, int y) {        if (-1 == res) { printf("God please help our poor hero.\nFINISH\n"); return; }        int fx, fy;        vector<int> path;        for (;;) {            fx = fa[x][y] / Mod;            fy = fa[x][y] % Mod;            if (!x && !y) break;            path.push_back(dir[x][y]);            x = fx, y = fy;        }        printf("It takes %d seconds to reach the target position, let me show you the way.\n", res);        fx = fy = 0;        for (int i = sz(path) - 1, j = 1; ~i && j <= res; i--) {            x = fx + dx[path[i]], y = fy + dy[path[i]];            char &ch = maze[x][y];            if ('0' <= ch && ch <= '9') {                int t = ch - '0';                printf("%ds:(%d, %d)->(%d, %d)\n", j++, fx, fy, x, y);                while (t--) printf("%ds:FIGHT AT (%d,%d)\n", j++, x, y);            }            else printf("%ds:(%d, %d)->(%d, %d)\n", j++, fx, fy, x, y);            fx = x, fy = y;        }        puts("FINISH");    }}int main() {#ifdef LOCAL    freopen("in.txt", "r", stdin);    freopen("out.txt", "w+", stdout);#endif    while (~scanf("%d %d", &N, &M)) {        rep(i, N) scanf("%s", maze[i]);        work::bfs();        work::show_path(N - 1, M - 1);    }    return 0;}