A. Little Elephant and Function
http://codeforces.com/problemset/problem/221/A
time limit per test
memory limit per test
input
output
The Little Elephant enjoys recursive functions.
a is a permutation of an integers from 1 to n, inclusive, and ai denotes the i-th element of the permutation. The Little Elephant's recursive function f(x), that sorts the first x
- x = 1, exit the function.
- f(x - 1), and then make swap(ax - 1, ax) (swap the x-th and (x - 1)-th elements of a).
n, such that after performing the Little Elephant's function (that is call f(n)), the permutation will be sorted in ascending order.
Input
n (1 ≤ n ≤ 1000)
Output
n distinct integers from 1 to n
It is guaranteed that the answer exists.
Sample test(s)
input
1
output
1
input
2
output
2 1
从后往前反推+找规律。
完整代码:
/*30ms,0KB*/
#include<cstdio>
int main(void)
{
int n;
scanf("%d", &n);
if (n == 1)
putchar('1');
else
{
printf("%d", n);
for (int i = 1; i < n; ++i)
printf(" %d", i);
}
return 0;
}