c++ - function returns all the same random number -

c++ - function returns all the same random number -

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how generate different random numbers in loop in c++? 12 answers

i have function in c++, returns random float number between 2 numbers. here code:

float randfloatnumbetween(float lower, float upper) { srand((unsigned)time(null)); homecoming lower + ((float) rand() / rand_max) * (upper - lower); }

when phone call function parameters lower 0.0 , upper 10.0, returns numbers like:

1.00503555 1.01846383 1.03463534 1.05263234 1.06461514

how can create function returns different numbers before , after comma? numbers like:

5.00503555 3.01846383 1.03463534 4.05263234 8.06461514

obviously need alter seed value each time phone call srand. based on comments you've left doesn't appear problem, needs pointed out.

some random number generators (i know microsoft's rand one) have correlation between initial seed , first number generated. since time doesn't alter fast, numbers seeding tend correlated well.

the best way around utilize improve random number generator such c++11 ones in <random> header: http://en.cppreference.com/w/cpp/numeric/random or predecessors in boost library.

otherwise create sure generate couple of throw-away random numbers after seed it.

c++ random