51 lines
1.3 KiB
Java
51 lines
1.3 KiB
Java
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public class left_rotation{
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public static void rotateToLeft(int [] arr){
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if(arr == null || arr.length == 0){
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System.out.println("no rotation possible");
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return;
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}
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//take the first element
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int firstElement = arr[0];
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//move everything in the left
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for(int i = 0; i < arr.length -1; i++){
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arr[i] = arr[i + 1];
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}
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//the first element become the last element
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arr[arr.length - 1] = firstElement;
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}
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public static void print(int [] arr){
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System.out.print("[");
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for(int i = 0; i < arr.length; i++)
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System.out.print(arr[i] + ", ");
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System.out.println("]");
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}
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public static void main(String [] args){
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int [] arr = {1,2,3,4,5,6,7,8,9};
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int n = 3; //number of times to rotate the array
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System.out.print("before: ");
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print(arr);
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System.out.println("rotating " + n + " times to left");
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for(int i = 0; i < n; i++)
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rotateToLeft(arr); //move to left n times
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System.out.print("after: ");
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print(arr);
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}
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}
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/*
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to run the file:
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javac left_rotation.java
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java left_rotation
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result:
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before: [1, 2, 3, 4, 5, 6, 7, 8, 9, ]
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rotating 3 times to left
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after: [4, 5, 6, 7, 8, 9, 1, 2, 3, ]
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*/
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