HackerRank Sam and substrings Problem Solution

In this post, we will solve HackerRank Sam and substrings Problem Solution.

Samantha and Sam are playing a numbers game. Given a number as a string, no leading zeros, determine the sum of all integer values of substrings of the string.
Given an integer as a string, sum all of its substrings cast as integers. As the number may become large, return the value modulo 109 +7.
Example
n = ’42’
Here n is a string that has 3 integer substrings: 4. 2, and 42. Their sum is 48, and
48 modulo (10 power 9 +7)= 48.
Function Description
Complete the substrings function in the editor below.
substrings has the following parameter(s):
string n: the string representation of an integer
Returns
int: the sum of the integer values of all substrings in n. modulo 10 power 9 + 7
Input Format
A single line containing an integer as a string, without leading zeros.

Sample Input 0

Sample Output 0

Explanation 0

The substrings of 16 are 16, 1 and 6 which sum to 23.

Sample Input 1

Sample Output 1

Explanation 1

The substrings of 123 are 1, 2, 3, 12, 23, 123 which sum to 164.

Table of Contents

Sam and substrings Problem C Solution

#include<stdio.h>
#include<malloc.h>
#include<string.h>
#define mod 1000000007
int main()
{
	int i,j,n,k;
	char s[200001];
	scanf("%s",s);
	n=strlen(s);
	long long int val,count,ones;
	long long int a[200001];
	count=0;
	a[n]=0;
	ones=1;
	for(i=n-1;i>=0;i--)
	{
		//printf("%d*%lld+%lld\n",s[i]-'0',ones,a[i+1]);
		a[i]=((s[i]-'0')*(ones)+a[i+1])%mod;
		ones=(ones*10+1)%mod;
		count=(count+a[i])%mod;
	}
	printf("%lld\n",count);
	return 0;
}

Sam and substrings Problem C++ Solution

#include <cmath>
#include <cstdio>
#include <fstream>
#include <vector>
#include <iostream>
#include <algorithm>
#include <iomanip>
#define MOD 1000000007
using namespace std;



int len; 


void init();

int main() {
    
    init();
}

void init() {

 

    ios_base::sync_with_stdio(0);cin.tie(0);

    char in;
    long long int with_i = 0, with_ni = 0, last_i = 0, last_ni = 0, temp_i, temp_ni;
    int num ;
    int counter = 0;
    while( ((in =getchar()) != EOF) ){
        num = in-'0';

        with_ni = (with_ni + with_i)%MOD;
        with_i = ((with_i*10)%MOD + ((num)*(counter+1)%MOD))%MOD;
        //if(num){
            counter++;
        //}
    }
    cout<<(with_i+with_ni)%MOD<<endl;

    
 


    
}

Sam and substrings Problem C Sharp Solution

using System;
using System.Collections.Generic;
using System.IO;
class Solution {
    static void Main(String[] args) {
        string input = Console.ReadLine();
        double result = 0;
        double[] dp = new double[input.Length];
        for(int i = 0; i < input.Length; i++){
            double temp = Convert.ToDouble(input[i].ToString());
            dp[i] = (temp + i * temp + (i - 1 >= 0 ? 10 * dp[i - 1] : 0)) % 1000000007;
        }
        for(int i = 0; i < input.Length; i++){
            result = (result + dp[i]) % 1000000007;
        }
        Console.WriteLine(result % 1000000007);
    }
}

Sam and substrings Problem Java Solution

import java.io.*;
import java.util.*;
import java.lang.*;



class Solve{
    int mod = (int)Math.pow(10,9)+7;
    

    long totalSum(String s){
        long ans=0;
        int l = s.length();
        long [] a = new long[l+1];
        long [] b = new long[l+1];
        a[0] = 1;
        b[0] = 1;
        for(int i=1;i<l;i++){
            a[i] = (a[i-1]*10)%mod;
            b[i] = (b[i-1] +a[i])%mod ;
        }
        for(int i=0;i<l;i++){
            long temp = Integer.parseInt(s.substring(i,i+1));
            ans = (ans+(b[l-i-1]*temp*(i+1))%mod )%mod;
        }

        return ans;
    }
}


class Solution{
    public static void main(String[]args){
        Scanner sc = new Scanner(System.in);
        String s = sc.next();
        Solve slv = new Solve();
        long ans  = slv.totalSum(s);
        System.out.println(ans);   
    }
}

Sam and substrings Problem JavaScript Solution

var BigNumber = require('bignumber.js');

function processData(arr) {
    var sum = new BigNumber(0);
    var modulo = new BigNumber(1000000000).plus(7);

    for(var i = arr.length - 1, start = new BigNumber(1); i >= 0; i--) {
        if(arr[i] != '0') {
            var a = new BigNumber((arr[i] - '0') * (i + 1)).times(start);
        
            sum = sum.plus(a);
        }
        
        start = start.times(10).plus(1).modulo(modulo);
    }

    console.log(sum.modulo(modulo).toFixed());
}

process.stdin.resume();
process.stdin.setEncoding("ascii");
_input = "";
process.stdin.on("data", function (input) {
    _input += input;
});

process.stdin.on("end", function () {
   processData(_input);
});

Sam and substrings Problem Python Solution

#!/usr/bin/env python

def main():
	Mod=10**9+7
	s=[0]+list(map(int,list(input())))
	#print(s)
	n=len(s)
	ans=0
	now=0
	for i in range(1,n):
		now=(now*10+s[i]*i)%Mod
		ans=(ans+now)
		if ans>=Mod:
			ans-=Mod
	print(ans)




if __name__=='__main__':
	main()