Abstract

Large sums in C++.

A Very Big Sum

Problem

In this challenge, you are required to calculate and print the sum of the elements in an array, keeping in mind that some of those integers may be quite large.

Function Description

Complete the a_very_big_sum function in the editor below. It must return the sum of all array elements.

a_very_big_sum has the following parameter(s):

int ar[n]

an array of integers .

Return

long

the sum of all array elements

Input Format

The first line of the input consists of an integer \(n\).

The next line contains \(n\) space-separated integers contained in the array.

Output Format

Return the integer sum of the elements in the array.

Constraints

• \(1 \le n \le 10\)

• \(0 \le ar[i] \le 10^{10}\)

Sample Input

Sample Input

5 1000000001 1000000002 1000000003 1000000004 1000000005

Output

Output

5000000015

Note

The range of the 32-bit integer is \((-2^{31}) to (2^{31}) or [-2147483658,2147483657]\).

When we add several integer values, the resulting sum might exceed the above range. You might need to use long int C/C++/Java to store such sums.

Solution

a-very-big-sum.cpp

#include "stdc++.h"

using namespace std;

string ltrim(const string &);
string rtrim(const string &);
vector<string> split(const string &);

/*
 * Complete the 'aVeryBigSum' function below.
 *
 * The function is expected to return a LONG_INTEGER.
 * The function accepts LONG_INTEGER_ARRAY ar as parameter.
 */

long aVeryBigSum(vector<long> ar) {
    long value = 0;
    for (auto element : ar) {
        value = value + element;
    }
    return value;
}

int main()
{
    ofstream fout(getenv("OUTPUT_PATH"));

    string ar_count_temp;
    getline(cin, ar_count_temp);

    int ar_count = stoi(ltrim(rtrim(ar_count_temp)));

    string ar_temp_temp;
    getline(cin, ar_temp_temp);

    vector<string> ar_temp = split(rtrim(ar_temp_temp));

    vector<long> ar(ar_count);

    for (int i = 0; i < ar_count; i++) {
        long ar_item = stol(ar_temp[i]);

        ar[i] = ar_item;
    }

    long result = aVeryBigSum(ar);

    fout << result << "\n";

    fout.close();

    return 0;
}

string ltrim(const string &str) {
    string s(str);

    s.erase(
        s.begin(),
        find_if(s.begin(), s.end(), not1(ptr_fun<int, int>(isspace)))
    );

    return s;
}

string rtrim(const string &str) {
    string s(str);

    s.erase(
        find_if(s.rbegin(), s.rend(), not1(ptr_fun<int, int>(isspace))).base(),
        s.end()
    );

    return s;
}

vector<string> split(const string &str) {
    vector<string> tokens;

    string::size_type start = 0;
    string::size_type end = 0;

    while ((end = str.find(" ", start)) != string::npos) {
        tokens.push_back(str.substr(start, end - start));

        start = end + 1;
    }

    tokens.push_back(str.substr(start));

    return tokens;
}