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reformat documentation

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This commit is contained in:
Krishna Vedala
2020-05-28 21:46:18 -04:00
parent b122d659c3
commit 5698363bd7
1 changed files with 45 additions and 22 deletions
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67
search/ternary_search.cpp
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@@ -1,49 +1,57 @@
/*
/**
* \file
* \brief [Ternary search](https://en.wikipedia.org/wiki/Ternary_search)
* algorithm
*
* This is a divide and conquer algorithm.
* It does this by dividing the search space by 3 parts and
* using its property (usually monotonic property) to find
* the desired index.
*
* Time Complexity : O(log3 n)
* Space Complexity : O(1) (without the array)
* * Time Complexity : O(log3 n)
* * Space Complexity : O(1) (without the array)
*/
#include <iostream>
/*
/**
* The absolutePrecision can be modified to fit preference but
* it is recommended to not go lower than 10 due to errors that
* may occur.
*
*/
#define absolutePrecision 10
/**
* The value of _target should be decided or can be decided later
* by using the variable of the function.
*/
#define _target 10
#define absolutePrecision 10
#define MAX 10000000
int N = 21;
int A[MAX] = {1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 3, 4, 10};
#define MAX 10000000 ///< Maximum length of array
/*
/**
* get_input function is to receive input from standard IO
* @todo @christianbender Get input from STDIO or write input to memory as done
* above.
*/
void get_input() {
// TODO(christianbender): Get input from STDIO or write input to memory as
// done above.
}
void get_input() {}
/*
/**
* This is the iterative method of the ternary search which returns the index of
* the element.
* \param[in] left lower interval limit
* \param[in] right upper interval limit
* \param[in] A array to search in
* \param[in] target value to search for
* \returns index where the target value was found
* \returns -1 if target value not found
*/
int it_ternary_search(int left, int right, int A[], int target) {
while (1) {
if (left < right) {
if (right - left < absolutePrecision) {
for (int i = left; i <= right; i++)
if (A[i] == target) return i;
if (A[i] == target)
return i;
return -1;
}
@@ -69,15 +77,22 @@ int it_ternary_search(int left, int right, int A[], int target) {
}
}
/*
/**
* This is the recursive method of the ternary search which returns the index of
* the element.
* \param[in] left lower interval limit
* \param[in] right upper interval limit
* \param[in] A array to search in
* \param[in] target value to search for
* \returns index where the target value was found
* \returns -1 if target value not found
*/
int rec_ternary_search(int left, int right, int A[], int target) {
if (left < right) {
if (right - left < absolutePrecision) {
for (int i = left; i <= right; i++)
if (A[i] == target) return i;
if (A[i] == target)
return i;
return -1;
}
@@ -85,8 +100,10 @@ int rec_ternary_search(int left, int right, int A[], int target) {
int oneThird = (left + right) / 3 + 1;
int twoThird = (left + right) * 2 / 3 + 1;
if (A[oneThird] == target) return oneThird;
if (A[twoThird] == target) return twoThird;
if (A[oneThird] == target)
return oneThird;
if (A[twoThird] == target)
return twoThird;
if (target < A[oneThird])
return rec_ternary_search(left, oneThird - 1, A, target);
@@ -99,10 +116,13 @@ int rec_ternary_search(int left, int right, int A[], int target) {
}
}
/*
/**
* ternary_search is a template function
* You could either use it_ternary_search or rec_ternary_search according to
* preference.
* \param [in] N length of array
* \param[in] A array to search in
* \param[in] target value to search for
*/
void ternary_search(int N, int A[], int target) {
std::cout << it_ternary_search(0, N - 1, A, target) << '\t';
@@ -110,7 +130,10 @@ void ternary_search(int N, int A[], int target) {
std::cout << std::endl;
}
/** Main function */
int main() {
int N = 21;
int A[] = {1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 3, 4, 10};
get_input();
ternary_search(N, A, _target);
return 0;