February 2013 Bronze Problem 1: Message Relay

Result: 10/10 **********

relay.cpp

#include <iostream>
#include <fstream>
 
#define loopi(x) loop_start(i,x,0)
#define loopj(x) loop_start(j,x,0)
#define loop_start(i, x,s) for(int i = (s); i < (x); ++i)
#define loop_rev(a,x,stop) for(int a = (x); a >= (stop); --a)
 
using namespace std;

typedef unsigned short int ushort;

ushort findcows(ushort *cows, ushort N, ushort target){
 ushort counter = 0;
 loopi(N)
  if(cows[i] == target){
   counter += 1 + findcows(cows, N, i + 1);
  }
 return counter;
}

int main() {
 ofstream fout ("relay.out");
 ifstream fin ("relay.in");
 // get input
 ushort N;
 fin >> N;
 ushort *cows = new ushort[N];
 loopi(N)
  fin >> cows[i];
 // process
 // every cow that forwards to 0, cows that forward to those, cows to those, etc...
 ushort result = findcows(cows, N, 0);
 // output
 fout << result << endl;
 // cleanup
 fin.close();
 fout.close();
 delete[] cows;
 return 0;
}