Sum of long integer array in c++

Question

I know this question asked many times but I am facing different problem in my code, I try to calculate sum of long integers range between 2-15.

Code:

long array[20];
long NUMBERS;

cout << "How many numbers ? : ";
cin >> NUMBERS;
long sum=0;
for (int i = 0; i < NUMBERS;i++){

    cout << "Input number " << (i+1) << " : ";
    cin >> array[i];    
}

cout << "Calculate Sum" << endl;
for (int i = 0; i < NUMBERS;i++){
    sum = sum + array[i];
}

cout << "Sum is : " << sum << endl;

When I input these three numbers.

1234567
123456
12345

Output:

Sum is : 1370368

but actual answer is : 3703627.

I try these solutions summing-large-numbers and sum-of-alternate-elements-of-integer-array but still not get right solution, also how we can solve this problem if user input different number with different ranges.

What you mean with "actual answer is 3703627"? According to http://www.wolframalpha.com/input/?i=1234567%2B123456%2B12345, your program is correct. — ScheRas, Mar 19 '17 at 21:37
You don't need a second loop: just do `sum+=array[i];` in the first loop — HDJEMAI, Mar 19 '17 at 21:40
Using a debugger, enter 25 numbers and see what happens. :-) — Thomas Matthews, Mar 19 '17 at 21:41
@Omore you calculate on paper wrong! Align numbers under eachother from right to left.. — pergy, Mar 19 '17 at 21:50
@juanchopanza I am also really can't understand how this down voted. — Omore, Mar 19 '17 at 21:51
@pergy I am looking to find the solution through code by align numbers left to right. — Omore, Mar 19 '17 at 21:55
You claim to be trying to calculate the sum of some integers. Simple arithmetic doesn't have a concept of "alignment". — juanchopanza, Mar 19 '17 at 21:59

score 6 · Accepted Answer · answered Mar 19 '17 at 21:55

6

This isn't about programming, but math... Hope this helps: http://www.wikihow.com/Add-Large-Numbers

(As a simple example, add 1 and 11. What is the result? 12 or 21?)

answered Mar 19 '17 at 21:55

inabout

311
2
6

score 0 · Answer 2 · answered May 11 '19 at 11:15

my code sum large number with string. first you enter number of numbers you want to sum(to 25). and then you enter the number (to 180 'each number').

#include <iostream>
#include <stdlib.h>
using namespace std;
int main (){
    int band;
    cin >> band;
    string string_of_number[25];
    for (int i=0; i<band; i++){ //for get all string number
        cin >> string_of_number[i];
    }
    int strings_length[band];
    for (int i=0; i<band; i++){ //for get all length of strings
        strings_length[i]=string_of_number[i].length();
    }
    int answer[180];
    for(int i=0; i<180; i++){
        answer[i]=0;
    }
    int remaner=0;
    int sum=0;
    int last=180;
    for (int h=0; h<band; h++){ // for sum strings with sum answer one by one
        int j=179;
        for (int i=strings_length[h]; i>=0; i--){
        if(string_of_number[h][i]=='\0'){
            i--;
        }
        sum = (remaner + (string_of_number[h][i]-'0') + answer[j]) %10;
        remaner = ((string_of_number[h][i]-'0') + answer[j]) / 10;
        answer[j]=sum;
        if (i==0 && remaner>0){
            j--;
            answer[j]+=remaner;
            remaner=0;
        }
        if(last>j)
            last=j;
            j--;
           }
          }
        for(; last<180; last++){
        cout << answer[last];
        } 
   }

score -2 · Answer 3 · answered Mar 19 '17 at 21:41

-2

It seems that your program assumes all numbers are 7 digit:

1234567

123456[0]

12345[00]

answered Mar 19 '17 at 21:41

Ali Asadpoor

327
1
13

But the answer yes. – Ali Asadpoor Mar 19 '17 at 22:03
1

I couldn't imagine your mistake! I thought 3703627 is your output! – Ali Asadpoor Mar 19 '17 at 22:10

Sum of long integer array in c++

3 Answers3