Update subset_sum.cpp

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Swastika Gupta 2021-06-29 23:11:09 +05:30 committed by GitHub
parent 20560dc947
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@ -18,6 +18,7 @@ namespace backtracking {
/**
* @namespace Subsets
* @brief Functions for counting subsets in a given array with a given sum
* Time Complexity: O(sum*n), where the sum is the target sum and n is the size of the array.
*/
namespace Subsets {
/**
@ -32,16 +33,12 @@ std::uint64_t subset_sum(int sum, const std::vector<int> &in_arr) {
int count_of_subset = 0;
for (int i = 0; i < (1 << (nelement)); i++) {
std::vector<int> subset;
int check = 0;
for (int j = 0; j < nelement; j++) {
if (i & (1 << j)) {
subset.push_back(in_arr[j]);
check += (in_arr[j]);
}
}
int check = 0;
for (int k : subset) {
check += k;
}
if (check == sum) {
count_of_subset++;
}
@ -59,33 +56,31 @@ static void test() {
// Test 1
std::cout << "1st test ";
std::vector<int> array1 = {-7, -3, -2, 5, 8}; // input array
assert(backtracking::Subsets::subset_sum(0, array1) ==
2); // first argument in subset_sum function is the required sum and
// second is the input array
assert(backtracking::Subsets::subset_sum(0, array1) == 2); // first argument in subset_sum function is the required sum and second is the input array
std::cout << "passed" << std::endl;
// Test 2
std::cout << "2nd test ";
std::vector<int> array2 = {1, 2, 3, 3}; // input array
assert(backtracking::Subsets::subset_sum(6, array2) ==
3); // first argument in subset_sum function is the required sum and
// second is the input array
std::vector<int> array2 = {1, 2, 3, 3};
assert(backtracking::Subsets::subset_sum(6, array2) == 3); // here we are expecting 3 subsets which sum up to 6 i.e. {(1,2,3),(1,2,3),(3,3)}
std::cout << "passed" << std::endl;
// Test 3
std::cout << "3rd test ";
std::vector<int> array3 = {1, 1, 1, 1}; // input array
assert(backtracking::Subsets::subset_sum(1, array3) ==
4); // first argument in subset_sum function is the required sum and
// second is the input array
std::vector<int> array3 = {1, 1, 1, 1};
assert(backtracking::Subsets::subset_sum(1, array3) == 4); // here we are expecting 4 subsets which sum up to 1 i.e. {(1),(1),(1),(1)}
std::cout << "passed" << std::endl;
// Test 4
std::cout << "4th test ";
std::vector<int> array4 = {3, 3, 3, 3}; // input array
assert(backtracking::Subsets::subset_sum(6, array4) ==
6); // first argument in subset_sum function is the required sum and
// second is the input array
std::vector<int> array4 = {3, 3, 3, 3};
assert(backtracking::Subsets::subset_sum(6, array4) == 6); // here we are expecting 6 subsets which sum up to 6 i.e. {(3,3),(3,3),(3,3),(3,3)}
std::cout << "passed" << std::endl;
// Test 5
std::cout << "5th test ";
std::vector<int> array5 = {};
assert(backtracking::Subsets::subset_sum(6, array5) == 0); // here we are expecting 0 subsets which sum up to 6 i.e. we can select anything from an empty array
std::cout << "passed" << std::endl;
}