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# Fastest method to sum up the left diagonal elements of a square array

I've been observing people using the following method for summing up the left diagonal elements of a square array $$a$$ of dimensions $$n$$ by $$n$$:

 1 2 3 4 5 //s is an integer datatype which has been initialised to 0 beforehand for(int i = 0; i < n; i++) for(int j = 0; j < n; j++) if(i == j) s += a[i][j]; 

Wouldn't the following account for a faster method?

 1 2 for(int i = 0; i < n; i++) s += a[i][i]; 

Note by Arkajyoti Banerjee
5 months, 2 weeks ago

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