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Hi all, I'm so excited to write my first blog here.↵
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Last week I was helping my friend in tracing the recursion problem called **Generating subset**.↵
He had the code snippet, but he was not able to understand the flow of the program. So, I tried to explain the logic to him. I'm↵
happy that, my explanation made him clear on his doubts. I thought of sharing my explanation on tracing this problem by writing a new blog.↵
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**Problem statement:** <br>↵
Generate the subsets of given N elements using recursion.↵
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**Input:** <br>↵
1 2 3↵
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**output:** <br>↵
1 2 3 <br>↵
1 2 <br>↵
1 3 <br>↵
1 <br>↵
2 3 <br>↵
2 <br>↵
3 <br>↵
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**Explanation:** <br>↵
Subsets of [1,2,3] is null, {1}, {2}, {3}, {1, 2}, {1, 3}, {2, 3}.↵
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**code:** <br> ↵
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<pre class="prettyprint">↵
#include "bits/stdc++.h"↵
using namespace std;↵
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vector<int> subset;↵
void search(int a[], int n, int index) {↵
if(index == n){↵
// print the subset↵
for(int i=0; i<subset.size(); i++){↵
cout << subset[i] << " ";↵
}↵
cout << "\n";↵
}else{↵
subset.push_back(a[index)];↵
search(a, n, index+1);↵
subset.pop_back();↵
search(a, n, index+1);↵
}↵
}↵
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int main() {↵
int a[] = {1, 2, 3};↵
int n = sizeof(a)/sizeof(a[0]);↵
int startIndex = 0;↵
search(a, n, startIndex);↵
return 0;↵
}↵
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</pre>↵
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My explanation of this program is given below.↵
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This is my first blog ever in my life. If you find any mistakes or you have any suggestions, please let me know. So that I can improve it form next time. ↵
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Thank you.↵
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