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- DSA using C - Priority Queue
- DSA using C - Tree
- DSA using C - Hash Table
- DSA using C - Heap
- DSA using C - Graph
- DSA using C - Search techniques
- DSA using C - Sorting techniques
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DSA using C - Insertion Sort
Overview
Insertion sort is a simple sorting algorithm. This sorting algorithm is in-place comparison based algorithm in which a item is taken, its suitable location is searched and this item is inserted at that particular location growing the sorted list. This algorithm is not suitable for large data sets as its average and worst case complexity are of O(n2) where n are no. of items.
Pseudocode
procedure insertionSort( A : array of items ) int holePosition int valueToInsert for i = 1 to length(A) inclusive do: /* select value to be inserted */ valueToInsert = A[i] holePosition = i /*locate hole position for the element to be inserted */ while holePosition > 0 and A[i-1] > valueToInsert do: A[holePosition] = A[holePosition-1] holePosition = holePosition -1 end while /* insert the number at hole position */ A[holePosition] = valueToInsert end for end procedure
Example
#include <stdio.h> #include <stdbool.h> #define MAX 7 int intArray[MAX] = {4,6,3,2,1,9,7}; void printline(int count){ int i; for(i=0;i <count-1;i++){ printf("="); } printf("=\n"); } void display(){ int i; printf("["); // navigate through all items for(i=0;i<MAX;i++){ printf("%d ",intArray[i]); } printf("]\n"); } void insertionSort(){ int valueToInsert; int holePosition; int i; // loop through all numbers for(i=1; i < MAX; i++){ // select a value to be inserted. valueToInsert = intArray[i]; // select the hole position where number is to be inserted holePosition = i; // check if previous no. is larger than value to be inserted while (holePosition > 0 && intArray[i-1] > valueToInsert){ intArray[holePosition] = intArray[holePosition-1]; holePosition--; printf(" item moved : %d\n" , intArray[holePosition]); } if(holePosition!= i){ printf(" item inserted : %d, at position : %d\n" , valueToInsert,holePosition); // insert the number at hole position intArray[holePosition] = valueToInsert; } printf("Iteration %d#:",i); display(); } } main(){ printf("Input Array: "); display(); printline(50); insertionSort(); printf("Output Array: "); display(); printline(50); }
Output
If we compile and run the above program then it would produce following output −
Input Array: [4, 6, 3, 2, 1, 9, 7] ================================================== iteration 1#: [4, 6, 3, 2, 1, 9, 7] item moved :6 item moved :4 item inserted :3, at position :0 iteration 2#: [3, 4, 6, 2, 1, 9, 7] item moved :6 item moved :4 item moved :3 item inserted :2, at position :0 iteration 3#: [2, 3, 4, 6, 1, 9, 7] item moved :6 item moved :4 item moved :3 item moved :2 item inserted :1, at position :0 iteration 4#: [1, 2, 3, 4, 6, 9, 7] iteration 5#: [1, 2, 3, 4, 6, 9, 7] item moved :9 item moved :6 item inserted :7, at position :4 iteration 6#: [1, 2, 3, 4, 7, 6, 9] Output Array: [1, 2, 3, 4, 7, 6, 9] ==================================================
dsa_using_c_sorting_techniques.htm
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