Project Euler #8: Largest product in a series | Hackerrank | Project Euler

 Largest product in a series

Find the greatest product of K consecutive digits in the N digit number.

Input Format

First line contains T that denotes the number of test cases.

First line of each test case will contain two integers N & K.

Second line of each test case will contain a N digit integer.

Constraints

1<=T<=100

1<=K<=7

K<=N<=1000

Output Format

Print the required answer for each test case.

Sample Input 0

2

10 5

3675356291

10 5

2709360626

Sample Output 0

3150

0

Explanation 0

For 3675356291 and selecting K=5 consecutive digits, we have 36753, 67535, 75356, 53562, 35629 and 56291. Where 6*7*5*3*5 gives  maximum product as 3150

For 2709360626, 0 lies in all selection of 5 consecutive digits hence maximum product remains 0

Solution:

#include <map>

#include <set>

#include <list>

#include <cmath>

#include <ctime>

#include <deque>

#include <queue>

#include <stack>

#include <string>

#include <bitset>

#include <cstdio>

#include <limits>

#include <vector>

#include <climits>

#include <cstring>

#include <cstdlib>

#include <fstream>

#include <numeric>

#include <sstream>

#include <iostream>

#include <algorithm>

#include <unordered_map>

using namespace std;

int main(){

    int t;

    cin >> t;

    for(int a0 = 0; a0 < t; a0++){

        int n;

        int k;

        cin >> n >> k;

        string num;

        cin >> num;

    int j=k;

    int l=0;

    int max=0;

    while(j<=n)

    {

        int mul=1;

        for(int i=l;i<j;i++)

        {

            mul=(int)(num[i]-48)*mul;

        }

    

        j++;

        l++;

        

        if(mul>max)

        max=mul;

    }

     cout<<max<<endl;

    }

    return 0;

}

You can also run it on an online IDE :

https://ide.geeksforgeeks.org/1a3d68dc-6e98-408d-9c36-f0dd139e8f4d

Your feedback are always welcome! If you have any doubt you 

can contact me or leave a comment!  

Happy Coding!! Cheers!!!