Problem p03594 (C++)

Buggy submission (status: Runtime Error):
#include <algorithm>
#include <bitset>
#include <climits>
#include <complex>
#include <cstring>
#include <deque>
#include <exception>
#include <fstream>
#include <functional>
#include <iomanip>
#include <ios>
#include <iosfwd>
#include <iostream>
#include <istream>
#include <iterator>
#include <limits>
#include <list>
#include <locale>
#include <map>
#include <memory>
#include <new>
#include <numeric>
#include <ostream>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <stdexcept>
#include <streambuf>
#include <string>
#include <typeinfo>
#include <utility>
#include <valarray>
#include <vector>

#define rep(i, m, n) for (int i = int(m); i < int(n); i++)
#define all(c) begin(c), end(c)

template <typename T1, typename T2> inline void chmin(T1 &a, T2 b) {
  if (a > b)
    a = b;
}

template <typename T1, typename T2> inline void chmax(T1 &a, T2 b) {
  if (a < b)
    a = b;
}

typedef long long int ll;
using ll = long long int;
using ull = long long unsigned int;
using Int = long long int;
using namespace std;
#define INF (1 << 30) - 1
#define INFl (ll)5e15
#define DEBUG 0
#define dump(x) cerr << #x << " = " << (x) << endl
#define MOD 1000000007

// edit
class Solve {
public:
  Int H, W, d;

  void solve() {
    cin >> H >> W >> d;
    vector<vector<char>> col(2 * H, vector<char>(2 * W));
    for (int i = 0; i < 2 * H; ++i) {
      for (int j = 0; j < 2 * W; ++j) {
        string cnv[2] = {"RG", "BY"};

        Int r = (i / d) % 2;
        Int c = (j / d) % 2;
        col[i][j] = cnv[r][c];
      }
    }

    vector<vector<char>> ans(H, vector<char>(W));
    for (int i = 0; i < H; ++i) {
      for (int j = 0; j < W; ++j) {
        ans[i][j] = col[i + j][i - j + W];
        cout << ans[i][j];
      }
      cout << endl;
    }
  }
};

int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  cout << fixed << setprecision(10);

  Solve().solve();

  return 0;
}


Fixed submission:
#include <algorithm>
#include <bitset>
#include <climits>
#include <complex>
#include <cstring>
#include <deque>
#include <exception>
#include <fstream>
#include <functional>
#include <iomanip>
#include <ios>
#include <iosfwd>
#include <iostream>
#include <istream>
#include <iterator>
#include <limits>
#include <list>
#include <locale>
#include <map>
#include <memory>
#include <new>
#include <numeric>
#include <ostream>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <stdexcept>
#include <streambuf>
#include <string>
#include <typeinfo>
#include <utility>
#include <valarray>
#include <vector>

#define rep(i, m, n) for (int i = int(m); i < int(n); i++)
#define all(c) begin(c), end(c)

template <typename T1, typename T2> inline void chmin(T1 &a, T2 b) {
  if (a > b)
    a = b;
}

template <typename T1, typename T2> inline void chmax(T1 &a, T2 b) {
  if (a < b)
    a = b;
}

typedef long long int ll;
using ll = long long int;
using ull = long long unsigned int;
using Int = long long int;
using namespace std;
#define INF (1 << 30) - 1
#define INFl (ll)5e15
#define DEBUG 0
#define dump(x) cerr << #x << " = " << (x) << endl
#define MOD 1000000007

// edit
class Solve {
public:
  Int H, W, d;

  void solve() {
    cin >> H >> W >> d;
    vector<vector<char>> col(H + W, vector<char>(H + W));
    for (int i = 0; i < H + W; ++i) {
      for (int j = 0; j < H + W; ++j) {
        string cnv[2] = {"RG", "BY"};

        Int r = (i / d) % 2;
        Int c = (j / d) % 2;
        col[i][j] = cnv[r][c];
      }
    }

    vector<vector<char>> ans(H, vector<char>(W));
    for (int i = 0; i < H; ++i) {
      for (int j = 0; j < W; ++j) {
        ans[i][j] = col[i + j][i - j + W];
        cout << ans[i][j];
      }
      cout << endl;
    }
  }
};

int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  cout << fixed << setprecision(10);

  Solve().solve();

  return 0;
}