[恢]hdu 1030

2011-12-27 00:16:34

地址：http://acm.hdu.edu.cn/showproblem.php?pid=1030

题意：问图里两个数字之间最少需要多少步。

mark：注意小数在前大数在后，先算出行列，然后分奇偶。

代码：

# include <stdio.h>
# include <math.h>


int min(int a, int b){return a<b?a:b;}
int max(int a, int b){return a>b?a:b;}


int row(int n)
{
    int r = sqrt(1.0*n) ;
    if (r*r == n) return r ;
    else return r+1 ;
}


int col(int r, int n)
{
    return n-(r-1)*(r-1) ;
}


int gao(int r1, int c1, int r2, int c2)
{
    int range = c1 + (r2-r1)*2 ;
    if (c2 > range)
        return c2-range+gao(r1, c1, r2, range) ;
    if (c2 < c1)
        return c1-c2+gao(r1, c1, r2, c1) ;
    return (r2-r1)*2-((c2&1)==0) ;
}


int calc(int a, int b)
{
    int r1 = row(a), c1 = col(r1, a) ; 
    int r2 = row(b), c2 = col(r2, b) ;
    if ((c1&1)==0) return 1+min(gao(r1, c1-1, r2, c2), 
                             gao(r1, c1+1, r2, c2)) ;
    return gao(r1, c1, r2, c2) ;
}


int main ()
{
    int a, b ;
    while (~scanf ("%d %d", &a, &b))
        printf("%d\n", calc(min(a,b), max(a,b))) ;
    return 0 ;
}