[NBUT 1642 简单的图论问题?] dijkstra 模板

[NBUT 1642 简单的图论问题?] dijkstra 模板

题目链接：  [NBUT 1642 简单的图论问题?]

解题思路：第一个就是一个裸的最短路问题， 第二个答案就是一个三维的最短路。贴一个最短路模板

#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
using namespace std;

//#pragma comment(linker, "/STACK:1024000000,1024000000")

#define FIN             freopen("input.txt","r",stdin)
#define FOUT            freopen("output.txt","w",stdout)
#define fst             first
#define snd             second

typedef __int64  LL;
typedef pair PII;

const double eps = 1e-10;

const int MAXN = 500 + 5;
const int INF  = 0x3f3f3f3f;
const int DIR[][2] = {{ -1, 0}, {1, 0}, {0, -1}, {0, 1}};

int N, M, R1, C1, R2, C2;
int maze[MAXN][MAXN];
char buf[10];
struct Dijstra1 {
    struct QNode {
        PII pnt;
        int dis;
        QNode() {}
        QNode (PII pnt, int dis) : pnt (pnt), dis (dis) {}
        bool operator > (const QNode &e) const {
            return dis > e.dis;
        }
    };
    int mincost[MAXN][MAXN];
    bool vis[MAXN][MAXN];
    QNode tp;
    priority_queue, greater > Q;
    void init() {
        memset (mincost, 0x3f, sizeof (mincost) );
        memset (vis, false, sizeof (vis) );
        while (!Q.empty() ) Q.pop();
    }
    void run (int sx, int sy) {
        int x, y, nx, ny;
        mincost[sx][sy] = maze[sx][sy];
        Q.push (QNode (PII (sx, sy), mincost[sx][sy]) );
        while (!Q.empty() ) {
            tp = Q.top();
            Q.pop();
            x = tp.pnt.fst;
            y = tp.pnt.snd;
            if (vis[x][y]) continue;
            vis[x][y] = true;
            for (int i = 0; i < 4; i ++) {
                nx = x + DIR[i][0];
                ny = y + DIR[i][1];
                if (nx > N || nx < 1 || ny > M || ny < 1) continue;
                if (maze[nx][ny] == -1) continue;
                if (mincost[nx][ny] > mincost[x][y] + maze[nx][ny]) {
                    mincost[nx][ny] = mincost[x][y] + maze[nx][ny];
                    Q.push (QNode (PII (nx, ny), mincost[nx][ny]) );
                }
            }
        }
    }
} dij1;
struct Dijstra2 {
    struct QNode {
        PII pnt;
        int dis, dir;
        QNode() {}
        QNode (PII pnt, int dis) : pnt (pnt), dis (dis) {}
        QNode (PII pnt, int dis, int dir) : pnt (pnt), dis (dis), dir (dir) {}
        bool operator > (const QNode &e) const {
            return dis > e.dis;
        }
    };
    int mincost[MAXN][MAXN][4];
    bool vis[MAXN][MAXN][4];
    QNode tp;
    priority_queue, greater > Q;
    void init() {
        memset (mincost, 0x3f, sizeof (mincost) );
        memset (vis, false, sizeof (vis) );
        while (!Q.empty() ) Q.pop();
    }
    void run (int sx, int sy) {
        int x, y, nx, ny;
        for (int i = 0; i < 4; i++) {
            mincost[sx][sy][i] = maze[sx][sy];
            Q.push (QNode (PII (sx, sy), mincost[sx][sy][i], i) );
        }
        while (!Q.empty() ) {
            tp = Q.top();
            Q.pop();
            x = tp.pnt.fst;
            y = tp.pnt.snd;
            if (tp.dir != -1 && vis[x][y][tp.dir]) continue;
            if (tp.dir != -1) {
                vis[x][y][tp.dir] = true;
            }
            for (int i = 0; i < 4; i ++) {
                nx = x + DIR[i][0];
                ny = y + DIR[i][1];
                if (nx > N || nx < 1 || ny > M || ny < 1) continue;
                if (maze[nx][ny] == -1) continue;
                if (tp.dir == i) continue;
                if (mincost[nx][ny][i] > mincost[x][y][tp.dir] + maze[nx][ny]) {
                    mincost[nx][ny][i] = mincost[x][y][tp.dir] + maze[nx][ny];
                    Q.push (QNode (PII (nx, ny), mincost[nx][ny][i], i) );
                }
            }
        }
    }
} dij2;

int main() {
#ifndef ONLINE_JUDGE
    FIN;
    // FOUT;
#endif // ONLINE_JUDGE
    int cas = 0;
    int res1, res2;
    while (~scanf ("%d %d %d %d %d %d", &N, &M, &R1, &C1, &R2, &C2) ) {
        for (int i = 1; i <= N; i ++) {
            for (int j = 1; j <= M; j++) {
                scanf ("%s", buf);
                if (buf[0] == '*') {
                    maze[i][j] = -1;
                } else {
                    maze[i][j] = atoi (buf);
                }
            }
        }
        dij1.init();
        dij2.init();
        dij1.run (R1, C1);
        dij2.run (R1, C1);
        res1 = dij1.mincost[R2][C2];
        res2 = INF;
        for (int i = 0; i < 4; i++) {
            res2 = min (res2, dij2.mincost[R2][C2][i]);
        }
        if (res1 == INF) res1 = -1;
        if (res2 == INF) res2 = -1;
        printf ("Case %d: %d %d\n", ++cas, res1, res2);
    }
    return 0;
}