How calculate sum of values in std::vector

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sum of elements in a std::vector

I have std::vector<int> and I want to calculate the sum of all the values in that vector. Is there any built in function or I need to write my custom code?

score 32 · Accepted Answer · answered Jul 19 '11 at 06:21

32

Use the STL algorithm std::accumulate, in the numeric header.

#include <numeric>

    // ...
    std::vector<int> v;
    // ...
    int sum = std::accumulate(v.begin(), v.end(), 0);

answered Jul 19 '11 at 06:21

John Calsbeek

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https://stackoverflow.com/a/3221813/52074 has an important warning about `std::accumulate` – Trevor Boyd Smith May 24 '18 at 13:28

score 11 · Answer 2 · answered Jul 19 '11 at 06:20

11

accumulate(v.begin(), v.end(), 0);

Look here for more details.

answered Jul 19 '11 at 06:20

Petar Minchev

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score 1 · Answer 3 · answered Jul 19 '11 at 06:22

1

You would need to make your own custom code.

int sum = 0; for (int i = 0; i < myvector.size(); i++) sum += myvectory[i];

The answer is in the variable 'sum'.

answered Jul 19 '11 at 06:22

thephpdev

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This is not needed: std::accumulate does the same trick. – RvdK Jul 19 '11 at 06:23

How calculate sum of values in std::vector

3 Answers3