Permutation p is an ordered set of integers p 1, p 2, …, p n, consisting of n distinct positive integers not larger than n. We’ll denote as n the length of permutation p 1, p 2, …, p n.
Your task is to find such permutation p of length n, that the group of numbers |p 1 - p 2|, |p 2 - p 3|, …, |p n - 1 - p n| 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.
Examples
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.
Solution:
#include <cstring>
#include <vector>
#include <list>
#include <map>
#include <set>
#include <deque>
#include <stack>
#include <bitset>
#include <algorithm>
#include <functional>
#include <numeric>
#include <utility>
#include <sstream>
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <ctime>
#include <memory.h>
#include <cassert>
using namespace std;
int a[1234567];
int main() {
int n, k;
scanf("%d %d", &n, &k);
a[0] = 1;
int low = 1, high = 1;
for (int i = 1; i <= k; i++) {
if (i % 2 == 1) {
a[i] = ++high;
} else {
a[i] = --low;
}
}
for (int i = k + 1; i < n; i++) {
if (a[k] == low) {
a[i] = a[i - 1] - 1;
} else {
a[i] = a[i - 1] + 1;
}
}
int smallest = a[0];
for (int i = 1; i < n; i++) {
if (a[i] < smallest) {
smallest = a[i];
}
}
for (int i = 0; i < n; i++) {
if (i > 0) printf(" ");
printf("%d", a[i] - smallest + 1);
}
printf("\n");
return 0;
}
Related posts:
Into Blocks (easy version)
MP3
Developing Game
Inversions problem
Vanya and Field
Scaygerboss
Context Advertising
Pillars
Tree-String Problem
Cube Problem
Generate a String
Primitive Root
Divisor Paths
Subarray Cuts
Field expansion
Optimal schedule of jobs given their deadlines and durations
Koala and Lights
Mateusz and an Infinite Sequence
Sieve of Eratosthenes Having Linear Time Complexity
Jordan Smiley
Friends
Bulbo
Washer, Dryer, Folder
Distinct Paths
Remove Duplicates
Photo to Remember
New Year and the Treasure Geolocation
Wonder Room
Minimum spanning tree - Prim's algorithm
Kay and Eternity
Vladislav and a Great Legend
Bogosort