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Merge.java
61 lines (58 loc) · 1.58 KB
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Merge.java
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/*
Please note that it's Function problem i.e.
you need to write your solution in the form of Function(s) only.
Driver Code to call/invoke your function would be added by GfG's Online Judge.*/
/* The task is to complete merge() which is used
in below mergeSort() */
class GfG
{
// 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)
{
int[] arr1 = new int[m - l + 1];
int[] arr2 = new int[r - m];
for (int i = 0; i < arr1.length; i++) {
arr1[i] = arr[i + l];
}
for (int i = 0; i < arr2.length; i++) {
arr2[i] = arr[m + 1 + i];
}
int i = 0;
int j = 0;
int k = l;
while (i < arr1.length && j < arr2.length) {
if (arr1[i] < arr2[j]) {
arr[k] = arr1[i];
k++;
i++;
} else if (arr1[i] >= arr2[j]) {
arr[k] = arr2[j];
k++;
j++;
}
}
while (i < arr1.length) {
arr[k] = arr1[i];
k++;
i++;
}
while (j < arr2.length) {
arr[k] = arr2[j];
k++;
j++;
}
}
}
/* This method is present in a class other than GfG class .
static void mergeSort(int arr[], int l, int r)
{
GfG g = new GfG();
if (l < r)
{
int m = (l+r)/2;
mergeSort(arr, l, m);
mergeSort(arr , m+1, r);
g.merge(arr, l, m, r);
}
}*/