content: package cn;
  
  /* Java program for Merge Sort */
  class merge
  { 
  	// Merges two subarrays of arr[]. 
  	// First subarray is arr[l..m] 
  	// Second subarray is arr[m+1..r] 
  	void merge(int arr[], int l, int m, int r) 
  	{ 
  		// Find sizes of two subarrays to be merged 
  		int n1 = m - l + 1; 
  		int n2 = r - m; 
  
  		/* Create temp arrays */
  		int L[] = new int [n1]; 
  		int R[] = new int [n2]; 
  
  		/*Copy data to temp arrays*/
  		for (int i=0; i<n1; ++i) 
  			L[i] = arr[l + i]; 
  		for (int j=0; j<n2; ++j) 
  			R[j] = arr[m + 1+ j]; 
  
  
  		/* Merge the temp arrays */
  
  		// Initial indexes of first and second subarrays 
  		int i = 0, j = 0; 
  
  		// Initial index of merged subarry array 
  		int k = l; 
  		while (i < n1 && j < n2) 
  		{ 
  			if (L[i] <= R[j]) 
  			{ 
  				arr[k] = L[i]; 
  				i++; 
  			} 
  			else
  			{ 
  				arr[k] = R[j]; 
  				j++; 
  			} 
  			k++; 
  		} 
  
  		/* Copy remaining elements of L[] if any */
  		while (i < n1) 
  		{ 
  			arr[k] = L[i]; 
  			i++; 
  			k++; 
  		} 
  
  		/* Copy remaining elements of R[] if any */
  		while (j < n2) 
  		{ 
  			arr[k] = R[j]; 
  			j++; 
  			k++; 
  		} 
  	} 
  
  	// Main function that sorts arr[l..r] using 
  	// merge() 
  	void sort(int arr[], int l, int r) 
  	{ 
  		if (l < r) 
  		{ 
  			// Find the middle point 
  			int m = (l+r)/2; 
  
  			// Sort first and second halves 
  			sort(arr, l, m); 
  			sort(arr , m+1, r); 
  
  			// Merge the sorted halves 
  			merge(arr, l, m, r); 
  		} 
  	} 
  
  	/* A utility function to print array of size n */
  	static void printArray(int arr[]) 
  	{ 
  		int n = arr.length; 
  		for (int i=0; i<n; ++i) 
  			System.out.print(arr[i] + " "); 
  		System.out.println(); 
  	} 
  
  	// Driver method 
  	public static void main(String args[]) 
  	{ 
  		int arr[] = {12, 11, 13, 5, 6, 7}; 
  
  		System.out.println("Given Array"); 
  		printArray(arr); 
  
  		merge ob = new merge(); 
  		ob.sort(arr, 0, arr.length-1); 
  
  		System.out.println("\nSorted array"); 
  		printArray(arr); 
  	} 
  } 
  
  