http://codeforces.com/contest/483/problem/C
C. Diverse Permutation
time limit per test
1 secondmemory limit per test
256 megabytesinput
standard inputoutput
standard outputPermutation p is an ordered set of integers p1, p2, ..., pn, consisting of n distinct positive integers not larger than n. We'll denote as nthe length of permutation p1, p2, ..., pn.
Your task is to find such permutation p of length n, that the group of numbers |p1 - p2|, |p2 - p3|, ..., |pn - 1 - pn| has exactly k distinct elements.
Input
The single line of the input contains two space-separated positive integers n, k (1 ≤ k < n ≤ 105).
Output
Print n integers forming the permutation. If there are multiple answers, print any of them.
Sample test(s)
input
3 2
output
1 3 2
input
3 1
output
1 2 3
input
5 2
output
1 3 2 4 5
Note
By |x| we denote the absolute value of number x.
解题思路：形如1,n,2,n-1,3,n-2.....这样肯定是最优的，但题目要求你正好有k个不同的，那么可以构造出k-1个不同的之后根据k是否为偶数进行单调输出
1 #include <stdio.h>
2 #include <string.h>
3 #include <stdlib.h>
4
5 int main(){
6 int i, k, n, left, right;
7 while(scanf("%d %d", &n, &k) != EOF){
8 left = 1; right = n;
9 for(i = 1 ; i <= k; i++){
10 if(i&1){
11 printf("%d ", left++);
12 }
13 else{
14 printf("%d ", right--);
15 }
16 }
17 if(k&1){
18 while(left < right){
19 printf("%d ", left++);
20 }
21 printf("%d ", left);
22 }
23 else{
24 while(left < right){
25 printf("%d ", right--);
26 }
27 printf("%d ", right);
28 }
29 }
30 return 0;
2 #include <string.h>
3 #include <stdlib.h>
4
5 int main(){
6 int i, k, n, left, right;
7 while(scanf("%d %d", &n, &k) != EOF){
8 left = 1; right = n;
9 for(i = 1 ; i <= k; i++){
10 if(i&1){
11 printf("%d ", left++);
12 }
13 else{
14 printf("%d ", right--);
15 }
16 }
17 if(k&1){
18 while(left < right){
19 printf("%d ", left++);
20 }
21 printf("%d ", left);
22 }
23 else{
24 while(left < right){
25 printf("%d ", right--);
26 }
27 printf("%d ", right);
28 }
29 }
30 return 0;
31 }