Weird behaviour of execution of same program with little modification multiple times?

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http://stackoverflow.com – Here, my question goes,I've written a C++ program and one of important blocks is that shuffles a vector. First time i'm seeding by 1 before shuffling it. I run this program. Now, i modify the source program by changing the seed value to 2 and rebuild it. If i run this program(the program names are same and first program is still running), what i expect is the shuffled vectors to be different. But, in my case i'm getting the same order of numbers in the shuffled vector. First time i run the program from terminal giving it a seed value of 1. Then i'll modify the source program to take a seed val (HowTos)