c++ - What is the most efficient way to find multiple sums from a file? -

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let's have file containing multiple rows of 3 columns:

3 1 3 1 2 3 4 5 6 . . .

the goal find sum of each column. solution simple: make 3 variables sum , 3 more temp variables.

however, solution doesn't scale well. if there 6 columns? i'd have make total of 12 variables. there other ways making count variable , temp variable , adding temp variable correct sum using modulus of count. seems hack.

is there better way of doing or c++ standard library meant this?

why not have single variable called sum , variable called temp. basic outline:

initialize sum 0; while there more lines:     read 1 line of input till \n found         while line has more inputs:             read each number out of (using temp)              sum += temp         next number         print out sum , reset 0     next line

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