Can someone explain me this code please?

Question

#include <vector>
#include <iostream>
using namespace std;

int main(void) {
vector<int> n = { 1,3,12,31,499393,1738391 }, v;
for (size_t i = 1; i <= 2000; i++) {
int n = i;
while (n-- > 0) v.push_back(i);
}
for(size_t i = 0; i < n.size(); i++)
cout << n[i] << " => " << v[n[i]-1] << endl;
}

Answer 1

after execution of the first loop we got our vector v as
v = {1, 2, 2, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 5, 6, 6, 6, 6, 6, 6, 7, 7, 7, 7, 7, 7, 7, 8, 8, 8, 8, 8, 8, 8, 8, 9, ...}

now to find the triangle no for 31 we just need to do:
answer: v[31-1] = 8.

Answer 2

~ swim ~ is truely a gems 💎 for SoloLearn. such a good answerer.

Answer 3

Hichem GOUIA thanks alot friend.

And happy learning!😄

Answer 4

~ swim ~ oh yes I get it 👍 big thanks friend
RKK yes I take a random java or c++ code and I try to understand it, so this time it was your code 😜 Great work

Answer 5

https://code.sololearn.com/cVQQ2zcVj1ni/?ref=app

Answer 6

Thanks for your explanation
Can you take the example of 31 and how it gives 8 as a result?
Thanks

Answer 7

Great explanation