+0  
 
+1
94
1
avatar

Hello Max! Can you please take a look at this question and see if you can arrive at the same answer (2,111) using combination and permutations?   https://web2.0calc.com/questions/set-theory

Thanks alot.

 Jun 14, 2020
 #1
avatar+8341 
0

Sorry, I am bad at combinatorics, but same as that Guest who answered your question, I wrote a program to verify Guest's answer, and it's correct. Here's my source code in C++:

 

#include
using namespace std;
string s = "122333444455555";
int main(){
    set se;
    do{
        se.insert(s.substr(0, 5));
    } while (next_permutation(s.begin(), s.end()));
    cout << se.size() << endl;
}

You can run it yourself on a suitable IDE(Integrated Development Environment) for C++, or just find one to run on by searching "online C++ IDE" on Google. You will see that the result is 2111.

 

Edit: I don't know why a part of my code keep disappearing. But the first line is \(\#\text{include}<\text{bits/stdc++.h}>\) and the fifth line is \(\text{set}<\text{string}> \text{se};\).

 Jun 14, 2020
edited by MaxWong  Jun 14, 2020
edited by MaxWong  Jun 14, 2020
edited by MaxWong  Jun 14, 2020
edited by MaxWong  Jun 14, 2020

32 Online Users

avatar
avatar
avatar