solution of problem A, codeforces contest 728, Div 2

Author: NirmalSilwal

Codeforces/livecontest/Round728Div2/A.java

@@ -0,0 +1,102 @@
+package livecontest.Round728Div2;
+
+import java.io.PrintWriter;
+import java.io.BufferedReader;
+import java.io.InputStreamReader;
+import java.io.IOException;
+import java.util.StringTokenizer;
+
+public class A {
+
+public static void main(String[] args) {
+
+FastReader sc = new FastReader();
+PrintWriter out = new PrintWriter(System.out);
+
+int t = sc.nextInt();
+for (int tt = 0; tt < t; tt++) {
+int x = sc.nextInt();
+solveTask(x);
+System.out.println();
+}
+
+out.close();
+}
+
+// 1 to n cats
+
+private static void solveTask(int n) {
+int[] arr = new int[n];
+for (int i = 1; i <= n; i++) {
+arr[i - 1] = i;
+}
+
+for (int i = 0; i < arr.length; i += 2) {
+if (i == (n - 1)) {
+swap(arr, i, i - 1);
+} else {
+swap(arr, i, i + 1);
+}
+}
+
+for (int i = 0; i < arr.length; i++) {
+System.out.print(arr[i] + " ");
+}
+}
+
+private static void swap(int[] arr, int i, int j) {
+int temp = arr[i];
+arr[i] = arr[j];
+arr[j] = temp;
+}
+
+static class FastReader {
+BufferedReader br;
+StringTokenizer st;
+
+FastReader() {
+br = new BufferedReader(new InputStreamReader(System.in));
+}
+
+String next() {
+while (st == null || !st.hasMoreElements()) {
+try {
+st = new StringTokenizer(br.readLine());
+} catch (IOException e) {
+e.printStackTrace();
+}
+}
+return st.nextToken();
+}
+
+int nextInt() {
+return Integer.parseInt(next());
+}
+
+long nextLong() {
+return Long.parseLong(next());
+}
+
+double nextDouble() {
+return Double.parseDouble(next());
+}
+
+String nextLine() {
+String str = "";
+try {
+str = br.readLine();
+} catch (IOException e) {
+e.printStackTrace();
+}
+return str;
+}
+
+int[] readArray(int n) {
+int[] temparr = new int[n];
+for (int i = 0; i < n; i++) {
+temparr[i] = nextInt();
+}
+return temparr;
+}
+}
+}