hdu2571命运【bfs】

#include<stdio.h>
#include<queue>
#include<string.h>
#include<iostream>
using namespace std;
#define N 25
#define M 1100
#define inf 0x3f3f3f3f
int map[N][M],max1,ans,n,m,book[N][M];

struct node{
    int x;
    int y,w;
};
queue<node>q;
void BFS()
{
    
    struct node head,tail,now;
    int x,y,i,j,d;
    head.x = 1;
    head.y = 1;
    head.w = map[1][1];
    q.push(head);
    while(!q.empty())
    {
        head = q.front();
    //    printf("x=%d y=%d w=%d\n",head.x,head.y,head.w );
        q.pop() ;
        if(head.x == n&&head.y == m)
        {
            if(head.w > max1)
                max1 = head.w ;
        }
        now.x = head.x + 1;
        now.y = head.y ;
        now.w = head.w + map[now.x][now.y];
        if(now.x >=1 &&now.y >= 1&&now.x <=n&&now.y<=m&&book[now.x][now.y] < now.w)
        {
            book[now.x][now.y] = now.w;
            q.push(now);
        }
        now.x = head.x;
        now.y = head.y +1;
        now.w = head.w + map[now.x][now.y];
        if(now.x >=1 &&now.y >= 1&&now.x <=n&&now.y<=m&&book[now.x][now.y] < now.w)
        {
            book[now.x][now.y] = now.w;
            q.push(now);
        }
        now.x = head.x;
        for(d = 2; d <= m; d ++)
        {
            now.y = head.y*d;
            if(now.y > m)
                break;
            now.w = head.w + map[now.x][now.y];
            if(now.x >=1 &&now.y >= 1&&now.x <=n&&now.y<=m&&book[now.x][now.y] < now.w)
            {
                book[now.x][now.y] = now.w;
                q.push(now);
            }
        }
        
        
    }
    return ;
}
int main()
{
    int t,i,j;
    scanf("%d",&t);
    while(t --)
    {
        scanf("%d%d",&n,&m);
        memset(book,0,sizeof(book));
        for(i = 1; i <= n; i ++)
            for(j = 1; j <= m; j ++)
                scanf("%d",&map[i][j]);
        max1 = -inf;
        BFS();
        printf("%d\n",max1);        
    }
    return 0;
}