uva 439 - Knight Moves

#include <iostream>#include <cstdio>#include <cstring>#include <cmath>#include <algorithm>using namespace std;int vis[10][10], ans[100];;int step[10][3]= {{1,2},{1,-2},{-1,2},{-1,-2},{2,1},{-2,1},{2,-1},{-2,-1}};int bfs(int x1, int y1, int x2, int y2){    int front = 0, rear = 1, list[100][3];    list[front][0] = x1;    list[front][1] = y1;    vis[x1][y1] = 1;    ans[front] = 0;    while(front < rear)    {        for(int i = 0; i < 8; i++)        {            int x = step[i][0] + list[front][0], y = step[i][1] + list[front][1];            if(x>0 && x<=8 && y>0 && y<=8 && !vis[x][y])            {                if(x == x2 && y == y2) return ans[front]+1;                list[rear][0] = x;                list[rear][1] = y;                ans[rear++] = ans[front] + 1;                vis[x][y] = 1;            }        }        front++;    }    return 0;}int main(){    char s1[3], s2[3];    while(cin >> s1 >> s2)    {        memset(vis, 0, sizeof(vis));        memset(ans, 0, sizeof(ans));        int count = bfs(s1[1]-'0', s1[0]-'a'+1, s2[1]-'0', s2[0]-'a'+1);        printf("To get from %s to %s takes %d knight moves.\n", s1, s2, count );    }    return 0;}