Problem 99: Broken Necklace

First attempt! w00t! For the last Section 1.1 too!

We're clearly supposed to brute-force every possibility.
Just traverse the maximum number of beads from each possible starting point.

/*
ID: victor4
PROG: beads
LANG: C++
*/
#include <iostream>
#include <fstream>
#include <string>

using namespace std;

int main() {
 ofstream fout ("beads.out");
 ifstream fin ("beads.in");
 int N;
 fin >> N;
 string beads;
 fin >> beads;
 
 if(beads.length() != N)
  // either this or we could throw a fatal error
  N = beads.length();
 
 // brute-force all possibilities
 int cur = 0, max = 0;
 char color;
 bool switched;
 
 for(int i = 0; i < N; ++i){
  // complexity O(n)
  cur = 0;
  switched = false;
  color = 'w';
  for(int j = 0; j < N; ++j){
   // complexity O(n^2)
   const char cur_c = beads[(i + j) % N];
   // always take white beads
   if(cur_c != 'w'){
    // first non-white
    if(color == 'w'){
     color = cur_c;
    }
    else if(color != cur_c){
     if(switched)
      break;
     else{
      color = cur_c;
      switched = true;
     }
    }
   }
   ++cur;
  }
  if(cur > max)
   max = cur;
 }
 
 fout << max << endl;
 return 0;
}