ZOJ 1871 Steps

Steps

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Time Limit: 2 Seconds      Memory Limit: 65536 KB

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One steps through integer points of the straight line. The length of a step must be nonnegative and can be by one bigger than, equal to, or by one smaller than the length of the previous step. 

What is the minimum number of steps in order to get from x to y? The length of the first and the last step must be 1.

Input

For each test case, a line follows with two integers: 0 <= x <= y < 2^31.

Output

For each test case, print a line giving the minimum number of steps to get from x to y.

Sample Input

45 48
45 49
45 50

Sample Output

3
3
4

题意：第一次和最后一次只能走1步，中间的步伐长度以1的长度递增或递减，如12321.

思路：找规律的题目，规律是步数为1的数有1个步数为2的数有1个，步数为3的数有2个，步数为4的数为2个,步数为5的数有3个，步数为6的数有3个
以此推下去数为1＋1＋2＋2＋3＋3......如果这个数是第一次出现则步数为2*i-1,第2次出现为2*i

代码：

#include <stdio.h>


int main()
{
    int m,n;
    int i,j;
    while (scanf("%d%d",&m,&n)!=EOF) {
        int sum=0,flag=0;
        if(n-m==0)
        {
          printf("0\n");
            continue;
        }
        for(i=1;;i++)
        {
            for(j=0;j<2;j++)
            {
                sum+=i;
               if((n-m)<=sum)
               {
                   flag=1;
                   break;
               }
            }
            if(flag==1)
                break;
        }
        if(j==1)
            printf("%d\n",2*i);
        else
            printf("%d\n",2*i-1);
    }
    return 0;
}