59 lines
1.3 KiB
C++
59 lines
1.3 KiB
C++
// C++ program to implement interpolation search
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#include<bits/stdc++.h>
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using namespace std;
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// If x is present in arr[0..n-1], then returns
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// index of it, else returns -1.
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int interpolationSearch(int arr[], int n, int x)
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{
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// Find indexes of two corners
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int lo = 0, hi = (n - 1);
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// Since array is sorted, an element present
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// in array must be in range defined by corner
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while (lo <= hi && x >= arr[lo] && x <= arr[hi])
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{
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if (lo == hi)
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{
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if (arr[lo] == x) return lo;
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return -1;
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}
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// Probing the position with keeping
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// uniform distribution in mind.
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int pos = lo + (((double)(hi - lo) /
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(arr[hi] - arr[lo])) * (x - arr[lo]));
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// Condition of target found
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if (arr[pos] == x)
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return pos;
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// If x is larger, x is in upper part
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if (arr[pos] < x)
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lo = pos + 1;
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// If x is smaller, x is in the lower part
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else
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hi = pos - 1;
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}
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return -1;
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}
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// Driver Code
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int main()
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{
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// Array of items on which search will
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// be conducted.
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int arr[] = {10, 12, 13, 16, 18, 19, 20, 21,
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22, 23, 24, 33, 35, 42, 47};
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int n = sizeof(arr)/sizeof(arr[0]);
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int x = 18; // Element to be searched
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int index = interpolationSearch(arr, n, x);
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// If element was found
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if (index != -1)
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cout << "Element found at index " << index;
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else
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cout << "Element not found.";
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return 0;
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} |