UVa：846 - Steps

注意：“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.”相邻两步的步长只能相差1或者相等。

模拟一下，即能找出规律：

x和y间的距离	每步的步长	总步数
0	0	0
1	1	1
2	1 1	2
3	1 1 1	3
4	1 2 1	3
5	1 2 1 1	4
6	1 2 2 1	4
7	1 2 2 1 1	5
8	1 2 2 2 1	5
9	1 2 3 2 1	5
10	1 2 3 2 1 1	6
11	1 2 3 2 2 1	6
12	1 2 3 3 2 1	6
13	1 2 3 3 2 1 1	7
14	1 2 3 3 2 2 1	7
15	1 2 3 3 3 2 1	7
16	1 2 3 4 3 2 1	7

步长最长为n = sqrt[distance(x,y)]。

当n * n == distance(x,y)时，总步数count = 2 * n - 1；

当distance(x,y) - n * n <= n时，count = 2 * n；

当distance(x,y) - n * n > n时，count = 2 * n + 1；

#include
#include
int main() {
    int c;
    while(scanf("%d", &c) != EOF) {
        while(c--) {
            int x, y;
            scanf("%d %d", &x, &y);
            int distance = y - x;
            int n = sqrt(distance);
            if(distance <= 3)
                printf("%d\n", distance);
            else if(n * n == distance)
                printf("%d\n", 2 * n - 1);
            else if(distance - n * n <= n)
                printf("%d\n", 2 * n);
            else
                printf("%d\n", 2 * n + 1);
        }
    }
    return 0;
}

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