Spam Classification Using Neural Net
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Neural nets are extremely popular in the Machine Learning domain. A neural net is composed of multiple layers. It has an input layer in which you input the parameter x (the input of the program). The input is then passed through multiple hidden layers, finally getting one output at the final layer, called the output layer.
We have a very simple neural net, which consist of N hidden layers. Each layer contains one neuron. Each neuron has two values associated with it: wi, and bi, denoting the weight and the bias of the neuron. If you give the neuron an input of x, it produces an output of (wi * x) + bi.
Thus, an input x gets transformed by the neural net as follows. The first hidden neuron takes the input x and produces y = w1 * x + b1, which acts as the input for the second neuron. Then, the second neuron takes input y and produces an output of z = w2 * y + b2. This keeps happening and you get a single output at the end from the N-th neuron.
There are some users and we want to find if they are spamming or not. They have integer user-ids, which range from minX to maxX (both inclusive). So we take each of these user-ids and feed it as input to the first layer of the neural net. If the final output is even, then that user is not a spammer, otherwise, the user is a spammer. You have to count the number of non-spammers and spammers.
- The first line of the input contains a single integer T denoting the number of test cases. The description of T test cases follows.
- The first line of each test case contains three space-separated integers N, minX, maxX.
- Each of the next N lines contains two space-separated integers wi and bi denoting the weight and the bias of the i-th neuron.
For each test case, output two space-separated integers denoting the number of non-spammers and the number of spammers, respectively.
- 1 ≤ T ≤ 10
- 1 ≤ N ≤ 105
- 1 ≤ minX ≤ maxX ≤ 109
- 1 ≤ wi, bi ≤ 109
Input 3 1 1 2 1 2 2 1 4 2 4 2 3 3 2 1000000000 2 4 2 2 5 4 Output 1 1 0 4 999999999 0
Example 1. There is a single neuron with weight = 1 and bias = 2. Let us check the output for x = 1: w * x + b = 1 * 1 + 2 = 3. Output for x = 2 would be 2 * 1 + 2 = 4. You can see that one of these is even and the other is odd. So, there is one spammer and one non-spammer.
Example 2. There are two neurons with weights 2 each, but bias 4, 3 respectively.
- x = 1, y = 2 * 1 + 4 = 6. z = 2 * 6 + 3 = 15
- x = 2, y = 2 * 2 + 4 = 8. z = 2 * 8 + 3 = 19
- x = 3, y = 2 * 3 + 4 = 10. z = 2 * 10 + 3 = 23
- x = 4, y = 2 * 4 + 4 = 12. z = 2 * 12 + 3 = 27
You can see that all of these are odd and hence signify that they are spammers. So, there are 0 non-spammers and 4 spammers.
|Tags||acm17kgp, admin2, easy, kgp17rol|
|Time Limit:||2 sec|
|Source Limit:||50000 Bytes|
|Languages:||C, CPP14, JAVA, PYTH, PYTH 3.6, PYPY, CS2, PAS fpc, PAS gpc, RUBY, PHP, GO, NODEJS, HASK, rust, SCALA, swift, D, PERL, FORT, WSPC, ADA, CAML, ICK, BF, ASM, CLPS, PRLG, ICON, SCM qobi, PIKE, ST, NICE, LUA, BASH, NEM, LISP sbcl, LISP clisp, SCM guile, JS, ERL, TCL, kotlin, PERL6, TEXT, SCM chicken, CLOJ, COB, FS|
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