Hey, I am trying to submit the source code of codechef sept challange Q code - "MNDIGSM2". But it reject my answer as "Runtime error"

Question

When i run the source code on sample cases of their example it runs fine but when I submit the question It says runtime error. Here is my Source code and link of the question. Question link - https://www.codechef.com/SEPT21C/submit/MNDIGSM2 Below is the code.

#include <iostream>
#include <vector>
// #include <bits/stdc++.h>
using namespace std;
// #define fast ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);

int converter(int n , int b){
    vector<int> vec;
    int sum = 0;
    while(n>0){
        vec.push_back(n%b);
        n = n / b;
        }
    int vecSize = vec.size();
        for(int i = 0;i<vecSize;i++){
            // cout<<
            sum = sum + vec[i];
        }
        return sum;
}
int minVal(vector<int> arr , int len){
    int min =  arr[0], c = 0;
    // if(arr)
    for(int i = 1 ; i< len;i++){
        if (arr[i] < min){
        min = arr[i];
        c = i;
        }
    }
    return c;
    
}
int main() {
    // your code goes here
    // fast;
    int test;
    cin>>test;
    while(test--){
        int n ,r;
        cin>>n>>r;
        int l = 2;
        // ll copy = l;
        int arSize = (r-2)+1;
        vector<int> arr(arSize);
        for(int i = 0;i< arSize ;i++){
            arr[i] = converter(n,l);
            l++;
        }
        int tobe = minVal(arr , arSize);
        cout<<tobe + 2<<endl;
    }
 
    return 0;
}

Answer 1

Maybe I do not understand the question fully. There is not enough information available.

It could be that the program slows down because the usage of the std::vector. First you calculate, then store the values and then iterate again over all values.

This is not necessary. You can do all calculations inline without the need for additional storage.

And, additionally, all these "contest" questions do not have the intention, to improve your programming skills.

Basically the language doesn't matter. The important thing is the algorithm. They want you to find a "good" algorithm.

Bruteforcing is nearly never a feasible solution. If you read about big numbers like 10^12, then you know already in advance that you will get a TLE with the brute force solution.

Regarding this horrible and non compliant C++ slang that is used on this "competetion" sides, please note that this is nearly never necessary. You have no time contraints to submit a solution. So, you could use also real C++ code.

Anyway. I corrected your code and added meaningful varibale names, comments and formatting. So, logically, the approach is the same, but it is readable.

Of course it may fail as well, because it is still brute forcing . . .

#include <iostream>
#include <limits>

constexpr unsigned long long BaseStart = 2ull;

int main() {

   // Get number of test cases
   unsigned int numberOfTestCases{};
   std::cin >> numberOfTestCases;

   // Work on all test cases 
   for (unsigned int testCase{}; testCase < numberOfTestCases; ++testCase) {

       // Get the value to check and the upper limit for the base 
       unsigned long long valueToCheck{}, upperLimitBase{};
       std::cin >> valueToCheck >> upperLimitBase;

       // Here we will store the minimum sum to check
       unsigned long long minimumsumOfDigits{std::numeric_limits<unsigned long long>::max()};

       // Here we will store the result
       unsigned long long minimumBase{};

       for (unsigned long long base{BaseStart}; base <= upperLimitBase; ++base) {

           // And this will be the running sumOfDigits
           unsigned long long runningSumOfDigits{};

           // get the digits of the value and calculate the running sum
           unsigned long long value{valueToCheck};
           
           while (value > 0) {

               // Get digits via modulo division and add up
               runningSumOfDigits += value % base;
               value /= base;
           }
           
           // Get current minimum
           if (runningSumOfDigits < minimumsumOfDigits) {
               minimumsumOfDigits = runningSumOfDigits;
               minimumBase = base;
           }
        }
        std::cout << minimumBase << '\n';
    }
    return 0;
}

This code can of course be optimized further, but for this I would need more information . . .