time estimation in visual c++ express 2010

hi all,

does anyone know how to find out the time taken in the program execution in ms visual c++ express 2010 ???

i have a feeling that a lot of my submissions are being rejected due to excess time taken by my source code…!!!

In fact you don’t need this, you do not need exact amount of time

  • server is slower than your PC
  • you still have to find worst case

Analyze your code and try to find out complexity of your algorithm. So if you find out, that your code complexity is O(N*M), you can assume that for 10.000.000 “operations” it will pass (for 1s timelimit). So if your max. N is 100.000 and max M is also 100.000 it won’t. The number of “operations” per second is not guarantied, but I believe that for 1s ~10.000.000 “operations” is ok.

For easier problems you can easily see, that if you use one inner loop

for ( int i = 0; i < N; ++i )
    for ( int j = 0; i < M; ++j ) 
        ...

the complexity is O(N*M).

Be aware that we are talking about asymptotic complexity (it means that we are interested in huge N) so
if your loops are

for ( int i = 0; i < N; ++i )
    for ( int j = i+1; i < M; ++j ) 
        ...

the complexity is O(N*M/2), but typically such constants are ignored and we are talking about O(N*M) complexity.

For more difficult problems you have to know something about data structures you are using or algorithms used for some problem classes…

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