UVa 467 - Synching Signals

Accepted date: 2014-07-09
Ranking (as of 2014-07-09): 84 out of 451
Language: C++

/*
  UVa 467 - Synching Signals

  To build using Visual Studio 2012:
    cl -EHsc -O2 UVa_467_Synching_Signals.cpp
*/

#include <iostream>
#include <string>
#include <sstream>
#include <cstring>
using namespace std;

const int nr_signals_max = 10, nr_seconds_max = 3600;
int signals[nr_signals_max];
bool seconds[nr_seconds_max + 1];

int main()
{
  for (int ds = 1; ; ds++) {
    string line;
    if (!getline(cin, line))
      break;
    istringstream iss(line);
    int nr_signals = 0, s;
    while (iss >> s)
      signals[nr_signals++] = s;
    memset(seconds, 0, sizeof(seconds));
    for (int i = 0; i < nr_signals; i++) {
      int c = signals[i] * 2, g = signals[i] - 5;
      for (s = c; s <= nr_seconds_max; s += c)
        for (int j = s; j < s + g && j <= nr_seconds_max; j++)
          seconds[j] = true;
    }
    for (s = 0; s <= nr_seconds_max; s++)
      if (seconds[s]) {
        int i;
        for (i = 0; i < nr_signals; i++) {
          int j = s / signals[i];
          if (!(j & 1) && s >= signals[i] * j &&
            s < signals[i] * (j + 1) - 5)
            ;
          else
            break;
        }
        if (i == nr_signals)
          break;
      }
    if (s <= nr_seconds_max)
      cout << "Set " << ds << " synchs again at " <<
        s / 60 << " minute(s) and " << s % 60 <<
          " second(s) after all turning green.\n";
    else
      cout << "Set " << ds << "is unable to synch after one hour.\n";
  }
  return 0;
}