hdu1026（bfs + priority_queue + 寻找路径）

来源：互联网发布：淘宝网国际转运服务编辑：程序博客网时间：2024/06/07 21:08
题目地址：http://acm.hdu.edu.cn/showproblem.php?pid=1026
题目本身不复杂，不过输出路径比较麻烦，不过又想练习用下优先队列，所以有了以下的代码：
<span style="font-size:18px;">#include <iostream>#include <algorithm>#include <cstdio>#include <cstring>#include <string>#include <queue>using namespace std;#define LL long longint flag[105][105];struct  node            //自定义结构的优先队列实现{    int x, y,step,f,index;    int distance;    friend bool operator < (node c, node b)    {        return c.step > b.step;//结构体中，x小的优先级高    }}a[10005];int drX[4] = {0,0,1,-1};int drY[4] = {1,-1,0,0};int ans[10005];int q;char s[105][105];void pnt(int index,int step){    if(a[index].f != -1)    {        if(s[a[index].x][a[index].y] == '.')        {            pnt(a[index].f,step - 1);            printf("%ds:(%d,%d)->(%d,%d)\n",step,a[a[index].f].x,a[a[index].f].y,a[index].x,a[index].y);        }        else        {            int time = s[a[index].x][a[index].y] - '0';            pnt(a[index].f,step - 1 - (s[a[index].x][a[index].y] - '0'));            printf("%ds:(%d,%d)->(%d,%d)\n",step - time,a[a[index].f].x,a[a[index].f].y,a[index].x,a[index].y);            for(int i = 0;i < time;i++)            {                printf("%ds:FIGHT AT (%d,%d)\n",step + i - time + 1,a[index].x,a[index].y);            }        }    }}int main(){    int n,m,k;    priority_queue <node> pq;    while(cin >> n >> m)    {        for(int i = 0;i < n;i++)        {            scanf("%s",s[i]);        }        while(pq.empty() == false) pq.pop();        memset(flag,0,sizeof(flag));        int pre = 0,rear = 1,nextX,nextY,ans;        a[0].distance = n + m - 2; a[0].step = 0;        a[0].x = 0; a[0].y = 0; a[0].f = -1; a[0].index  = 0;        pq.push(a[0]);        struct node tmp;        flag[0][0] = 1;        q = 0;        bool sign = true;        while(pq.empty() == false && sign == true)        {            tmp = pq.top();            pq.pop();            for(int i = 0;i < 4;i++)            {                nextX = tmp.x + drX[i];                nextY = tmp.y + drY[i];                if(nextX >= 0 && nextY >= 0 && nextX < n && nextY < m && s[nextX][nextY] != 'X' && flag[nextX][nextY] == 0)                {                    flag[nextX][nextY] = 1;                    if(nextX == n - 1 && nextY == m - 1)                    {                        ans = tmp.step + 1;                        if(s[nextX][nextY] != '.') ans += s[nextX][nextY] - '0';                        printf("It takes %d seconds to reach the target position, let me show you the way.\n",ans);                        if(s[nextX][nextY] == '.') pnt(tmp.index,ans - 1);                        else pnt(tmp.index,ans - (s[nextX][nextY] - '0') - 1);                        if(s[nextX][nextY] != '.')                        {                            int time = s[nextX][nextY] - '0';                            printf("%ds:(%d,%d)->(%d,%d)\n",ans - time,tmp.x,tmp.y,nextX,nextY);                            for(int i = 0;i < time;i++)                            {                                printf("%ds:FIGHT AT (%d,%d)\n",ans + i - time + 1,nextX,nextY);                            }                        }                        else                        {                            printf("%ds:(%d,%d)->(%d,%d)\n",ans,tmp.x,tmp.y,nextX,nextY);                        }                        puts("FINISH");                        sign = false;                        break;                    }                    else                    {                        a[rear].x = nextX;                        a[rear].y = nextY;                        a[rear].step = tmp.step + 1;                        if(s[nextX][nextY] != '.') a[rear].step += (s[nextX][nextY] - '0');                        a[rear].f = tmp.index;                        a[rear].index = rear;                        a[rear].distance = (n - 1 - nextX) + (m - 1 - nextY);                        pq.push(a[rear++]);                    }                }            }        }        if(sign == true)        {            printf("God please help our poor hero.\nFINISH\n");        }    }    return 0;}</span>
0 0