◆◆1~N, 임의 순열의 다음순열 구하기◆◆

BAEKJOON_10972

@@ -0,0 +1,60 @@
+import java.io.*;
+import java.util.*;
+
+
+public class Main {
+    //1 3 2 4
+    public static boolean next_permutation(int[] arr){
+        int i = arr.length-1;
+
+        while(i>0 && arr[i-1] >= arr[i]){
+            i-=1;
+        }
+
+        if(i<=0){
+            return false;
+        }
+
+        int j =arr.length-1;
+        while(arr[j] <= arr[i-1]){
+            j-=1;
+        }
+
+        int temp = arr[i-1];
+        arr[i-1] = arr[j];
+        arr[j] =temp;
+
+        j=arr.length-1;
+        while(i<j){
+            temp = arr[i];
+            arr[i] = arr[j];
+            arr[j] = temp;
+            i+=1;
+            j-=1;
+        }
+        return true;
+    }
+
+    public static void main(String[] args) throws IOException{
+        BufferedReader br =new BufferedReader(new InputStreamReader(System.in));
+        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
+
+        int N = Integer.parseInt(br.readLine());        //N은 1~N 까지의 자연수 4 - 1,2,3,4
+
+        int[] arr = new int[N];
+        StringTokenizer st = new StringTokenizer(br.readLine());
+        for(int i=0; i<N; i++){
+            arr[i]=Integer.parseInt(st.nextToken());
+        }
+        //permutation
+
+        if(next_permutation(arr)){
+            for(int i=0; i<N; i++){
+                System.out.print(arr[i]+" ");
+            }
+            System.out.println();
+        }else{
+            System.out.println("-1");
+        }
+    }
+}