How can I calculate the complexity of a c++ code?

[phpuser123]

Calculate the complexity of the following C++ code fragment: [3]
count = 0;
for (i = 1; i <= n; i *= 2)
for (j = 1; j <= i; j++)
2
count++;
Note: You are required to show all your workings.

[weaknessforcats]

Start here http://en.wikipedia.org/wiki/Cyclomatic_complexity.

[phpuser123]

I managed to get the answer


Outer loop executes log n times.
Inner loop has cost k which doubles each time.


This is a clue,some1 gave me but I can't understand how he arrived to log n for the outer loop.......
Can any1 give me any indication hw,log n ws obtained ???

Thanks

[weaknessforcats]

Read this: http://en.wikipedia.org/wiki/Big_O_notation.

[donbock]

There are many measures of complexity. Which one are you being asked to provide?

[jkmyoung]

Aside: Did you calculate the final answer?
1 + 2 + 4 + 8 + ... + 2^m = 2^(m+1) - 1