81 lines
2.1 KiB
C
81 lines
2.1 KiB
C
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/* Program to search data in given array using ternary search */
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#include <stdio.h>
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#include <stdlib.h>
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// Function to search data in a given array
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int Ternary_search(int *arr,int l,int r,int to_search)
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{
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//split current array into 3 part
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int Mid1=l+(r-l)/3,Mid2=r-(r-l)/3;
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// data not found condition
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if(l>r)
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return -1;
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// if data found in Mid1 index then return index number
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else if(arr[Mid1]==to_search)
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return Mid1;
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// if data found in Mid2 index then return the index number
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else if(arr[Mid2]==to_search)
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return Mid2;
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//else if data not found at index Mid1 and Mid2 then search in middle part of array
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else if(arr[Mid1]<to_search&&arr[Mid2]>to_search)
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{
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Mid1=Mid1+1;
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Mid2=Mid2-1;
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}
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// if data is less than Mid index data then search in before index number of current
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else if(arr[Mid1]>to_search)
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{
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Mid2=Mid1-1;
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Mid1=l;
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}
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// if data is less than Mid index data then search in after index number of current
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else if(arr[Mid2]<to_search)
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{
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Mid1=Mid2+1;
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Mid2=r;
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}
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// recursive calling the function
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return Ternary_search(arr,Mid1,Mid2,to_search);
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}
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// driver code
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int main()
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{
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int n,*arr,i,to_search,res;
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printf("Enter size: ");
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// taking input
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scanf("%d",&n);
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// if the size entered is negative then make it positive one
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if(n<0)
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n=n*-1;
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// dynamically allocating array
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arr=(int*)malloc(sizeof(int)*n);
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for(i=0;i<n;i++)
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{
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scanf("%d",&arr[i]);
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}
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printf("Enter the number to search: ");
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// taking data to search
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scanf("%d",&to_search);
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// calling function to search index of given number and assign it in res
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res=Ternary_search(arr,0,n,to_search);
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// if res contain -1 that means data not found
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if(res==-1)
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printf("Data Not Found");
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else
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printf("Data found at index no: %d",res);
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return 0;
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}
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/*
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Input: Enter size: 5
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1,2,3,4,5
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Enter the number to search: 2
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Output: Data found at index no: 1
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Time complexity: O(log3 n)
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Space complexity: O(1)
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*/
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