[hoj]Knight Moves

BFS,先到达即停止。

//因为奇葩的内网而无故CE不止

/*This Code is Submitted by Iris for Problem 1440 at 2013-07-24 22:46:09*/#include <queue>#include <cstdio>#include <cstring>#include <string>using namespace std;int move[8][2] = {{-2,1},{-1,2},{1,2},{2,1},{-2,-1},{-1,-2},{1,-2},{2,-1}};typedef struct point{int x,y,step;}point;int main(){    char str[10];    while(gets(str)){        int map[8][8];        memset(map,-1,sizeof(map));        int r1,c1,r2,c2;        r1 = str[0] - 'a';        c1 = str[1] - '1';        r2 = str[3] - 'a';        c2 = str[4] - '1';        if(r1==r2&&c1==c2){            printf("To get from %c%c to %c%c takes %d knight moves.\n",str[0],str[1],str[3],str[4],0);            continue;            }        map[r1][c1] = 0;        queue<point> q;        point p0 = {r1,c1,0};        q.push(p0);        int ctn = 0;        while(!q.empty()){            point p = q.front();            q.pop();            for(int i=0;i<8;i++){                int tx = p.x + move[i][0];                int ty = p.y + move[i][1];                if(tx>=0 && tx<8 && ty>=0 && ty<8 && map[tx][ty]<0){                    if(tx==r2 && ty==c2){                        printf("To get from %c%c to %c%c takes %d knight moves.\n",                               str[0],str[1],str[3],str[4],p.step+1);                        ctn = 1;                        break;                        }                    point tmp = {tx, ty, p.step+1};                    q.push(tmp);                    map[tx][ty] = tmp.step;                    }                }            if(ctn) break;        }    }    return 0;}