67 lines
2.1 KiB
C++
67 lines
2.1 KiB
C++
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//Description : Merge Sort Algorithm
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#include<bits/stdc++.h>
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using namespace std;
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void merging(int arr[], int l, int h, int m) {
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int N1 = m - l + 1; //Left Array Size
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int N2 = h - m; //Right Array Size
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int left[N1];
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int right[N2];
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for (int i = 0; i < N1; i++) {
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left[i] = arr[l + i]; //Copy elements to left array
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}
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for (int j = 0; j < N2; j++) {
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right[j] = arr[m + 1 + j]; //Copy elements to right array
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}
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int i = 0;
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int j = 0;
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int k = l;
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while (i < N1 && j < N2) { //Inserting back the elements from left and right array
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if (left[i] <= right[j]) { //If left element is smaller than the right one then we push
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arr[k++] = left[i++]; //left element to our main array(arr)
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} else {
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arr[k++] = right[j++]; //else we push right element to the main array
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}
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}
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for (; i < N1; i++) { //These loop executes only when there is difference in size of
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arr[k++] = left[i]; //left and right array
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}
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for (; j < N2; j++) {
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arr[k++] = right[j];
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}
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return;
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}
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void merge_sort(int arr[], int l, int h) {
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if (l < h) {
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int mid = (l + ((h - l) / 2));
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merge_sort(arr, l, mid); //Recursively calling for elements before mid(including mid)
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merge_sort(arr, mid + 1, h); //Recursively calling for elements after mid
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merging(arr, l, h, mid); //Merging the two arrays
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}
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return;
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}
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int main() {
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int arr[] = { 1,0,13,7,6,2,16 };
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cout << "Array Before Sorting" << endl;
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for (int i = 0; i < 7; i++) {
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cout << arr[i] << " ";
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}
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cout << endl;
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merge_sort(arr, 0, 6);
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cout << "Array After Sorting" << endl;
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for (int i = 0; i < 7; i++) {
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cout << arr[i] << " ";
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}
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return 0;
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//Ex :Input : arr= { 1,0,13,7,6,2,16 };
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// Output
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// Array Before Sorting
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// 1 0 13 7 6 2 16
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// Array After Sorting
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// 0 1 2 6 7 13 16
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//Time Complexity :O(nlogn)
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//Auxiliary Space :O(n)
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//where n is the array size
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}
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