hdu 1026 Ignatius and the Princess I (BFS)

题目链接：http://acm.hdu.edu.cn/showproblem.php?pid=1026

bfs+保存路径   留存

#include<stdio.h>#include<string.h>#include<algorithm>struct{    int x,y,time,pre;}q[110*110];int n,m,vis[110][110],xx[110][110];char s[110][110];int dx[]={1,-1,0,0};int dy[]={0,0,-1,1};void Print(int i){    if(q[i].pre!=-1)    {        Print(q[i].pre);        if(q[q[i].pre].x==q[i].x&&q[q[i].pre].y==q[i].y)            printf("%ds:FIGHT AT (%d,%d)\n",q[i].time,q[i].x,q[i].y);        else            printf("%ds:(%d,%d)->(%d,%d%)\n",q[i].time,q[q[i].pre].x,q[q[i].pre].y,q[i].x,q[i].y);    }}void bfs(){    int front=0,rear=1,flag=0;    int i;    q[front].x=q[front].y=q[front].time=0;    q[front].pre=-1;    vis[0][0]=1;    while(front!=rear)    {        while(xx[q[front].x][q[front].y]>0)        {            xx[q[front].x][q[front].y]--;            q[rear].x=q[front].x;            q[rear].y=q[front].y;            q[rear].time=q[front].time+1;            q[rear].pre=front;            rear++;            front++;        }        int i;        for(i=0;i<4;i++)        {            int a=q[front].x+dx[i];            int b=q[front].y+dy[i];            if(a>=0&&a<n&&b>=0&&b<m&&!vis[a][b]&&s[a][b]!='X')            {                vis[a][b]=1;                q[rear].x=a;                q[rear].y=b;                q[rear].time=q[front].time+1;                q[rear].pre=front;            if(a==n-1&&b==m-1)            {                front=rear;                flag=1;                while(xx[q[front].x][q[front].y]>0)                {                    rear++;                    xx[q[front].x][q[front].y]--;                    q[rear].x=q[front].x;                    q[rear].y=q[front].y;                    q[rear].time=q[front].time+1;                    q[rear].pre=front;                    front=rear;                 }                 printf("It takes %d seconds to reach the target position, let me show you the way.\n",q[rear].time);                 Print(front);                 break;            }            rear++;            }        }        front++;        if(flag) break;    }    if(flag==0)    printf("God please help our poor hero.\n");    printf("FINISH\n");}int main(){    while(scanf("%d%d",&n,&m)!=EOF)    {        int i,j;        memset(xx,0,sizeof(xx));        memset(vis,0,sizeof(vis));        for(i=0;i<n;i++)        {            scanf("%s",s[i]);            for(j=0;j<m;j++)            {                if(s[i][j]>='1'&&s[i][j]<='9')                xx[i][j]=s[i][j]-'0';            }        }        bfs();    }    return 0;}