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Get rid off double TwoDimArray[order][order].
Change MagicSquare to accept your new vector and get rid of the printfs (use std::cout).

What? Show your code.

Ah, I missed a >. Updated code:

std::vector<std::vector<double>> TwoDimArray(order, std::vector<double>(order));

std::vector<std::vector<double> TwoDimArray(order, std::vector<double>(order));

Be sure to put it after you read in order.