108 lines
2.3 KiB
C++
108 lines
2.3 KiB
C++
#include <iostream>
|
|
#include <vector>
|
|
|
|
// prototype of the sorting function
|
|
std::vector<int> sortVector(std::vector<int>& nums);
|
|
|
|
// function to print the elements of a vector
|
|
void printVector(const std::vector<int>& nums) {
|
|
for (int num : nums) {
|
|
std::cout << num << " ";
|
|
}
|
|
std::cout << std::endl;
|
|
}
|
|
|
|
int main() {
|
|
// test case 1
|
|
std::vector<int> test1 = {5, 2, 9, 1, 5, 6};
|
|
std::vector<int> result1 = sortVector(test1);
|
|
std::cout << "Test Case 1: Original Vector: ";
|
|
printVector(test1);
|
|
std::cout << "Sorted Vector: ";
|
|
printVector(result1);
|
|
std::cout << std::endl;
|
|
|
|
// test case 2
|
|
std::vector<int> test2 = {3, 8, 2, 7, 4};
|
|
std::vector<int> result2 = sortVector(test2);
|
|
std::cout << "Test Case 2: Original Vector: ";
|
|
printVector(test2);
|
|
std::cout << "Sorted Vector: ";
|
|
printVector(result2);
|
|
std::cout << std::endl;
|
|
|
|
return 0;
|
|
}
|
|
|
|
// merge two vectors which are already sorted
|
|
std::vector<int>& mergeVectors(std::vector<int>& v1, std::vector<int>& v2){
|
|
int size1 = v1.size();
|
|
int size2 = v2.size();
|
|
std::vector<int> v(size1+size2, 0);
|
|
int index1 = 0;
|
|
int index2 = 0;
|
|
int index = 0;
|
|
// traverse v1 and v2 at the same time
|
|
while(index1<size1 && index2<size2){
|
|
// whoever is smaller goes to v
|
|
if(v1[index1]<v2[index2]){
|
|
v[index] = v1[index1];
|
|
index1 = index1 + 1;
|
|
}else{
|
|
v[index] = v2[index2];
|
|
index2 = index2 + 1;
|
|
}
|
|
index = index + 1;
|
|
}
|
|
|
|
// if v1 is done, let's now deal with v2 left overs
|
|
if(index1>=size1){
|
|
while(index2<size2){
|
|
v[index] = v2[index2];
|
|
index++;
|
|
index2++;
|
|
}
|
|
}else{
|
|
// else means v2 is done. let's now deal with v1 left overs
|
|
while(index1<size1){
|
|
v[index] = v1[index1];
|
|
index++;
|
|
index1++;
|
|
}
|
|
}
|
|
return v;
|
|
}
|
|
|
|
// sort a vecotr of integers
|
|
std::vector<int> sortVector(std::vector<int>& nums) {
|
|
int size = nums.size();
|
|
// base case
|
|
if(size==1){
|
|
return nums;
|
|
}
|
|
// general case
|
|
// split the vector into two halves.
|
|
int mid = size/2;
|
|
|
|
// nums1 to store the first half, and nums2 to store the second half.
|
|
std::vector<int> nums1;
|
|
std::vector<int> nums2;
|
|
|
|
// copy the first half
|
|
for(int i=0;i<mid;i++){
|
|
nums1[i]=nums[i];
|
|
}
|
|
// copy the second half
|
|
for(int i=mid;i<size;i++){
|
|
nums2[i]=nums[i];
|
|
}
|
|
|
|
// make the recursive calls
|
|
nums1 = sortVector(nums1);
|
|
nums2 = sortVector(nums2);
|
|
|
|
// now that the two vectors are already sorted, let's merge them
|
|
return mergeVectors(nums1, nums2);
|
|
}
|
|
|