Problem p03263 (C++)

Buggy submission (status: Runtime Error):
//  Created by conan1024hao in 2019.
//  Copyright © 2019 conan1024hao. All rights reserved.
//  専用ライブラリです、自由にコピーして構いません。
//  感谢看我的代码！Wechat:conan1024hao QQ:810396815
#pragma GCC optimize("O3")
#include <algorithm>
#include <cctype>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <deque>
#include <iomanip>
#include <iostream>
#include <istream>
#include <iterator>
#include <list>
#include <map>
#include <ostream>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <utility>
#include <vector>
#define INF 10e16
#define MOD 1000000007
#define rep(i, a, n) for (ll i = a; i < (ll)(n); i++)
#define fi first
#define se second
#define pb push_back
#define mp make_pair
#define eb emplace_back
#define mmax(x, y) (x > y ? x : y)
#define mmin(x, y) (x < y ? x : y)
#define chmax(x, y) x = mmax(x, y)
#define chmin(x, y) x = mmin(x, y)
#define all(x) (x).begin(), (x).end()
#define siz(x) (ll)(x).size()
#define PI acos(-1.0)
using namespace std;
typedef long long int ll;
typedef pair<ll, ll> P;
long long GCD(long long a, long long b) { return b ? GCD(b, a % b) : a; }
long long LCM(long long a, long long b) { return a / GCD(a, b) * b; }
int dx[4] = {1, 0, -1, 0};
int dy[4] = {0, 1, 0, -1};
ll cmp(pair<ll, string> a, pair<ll, string> b) {
  if (a.fi != b.fi)
    return a.fi < b.fi;
  else
    return a.se < b.se;
}

//---------------------------------------------------------------------------

//---------------------------------------------------------------------------
int main() { // 問題をちゃんと見ろ!!!!!!!!!!!!!!!!!      llか??????????
  cin.tie(0);
  ios::sync_with_stdio(false);
  //-------------------------------
  int h, w;
  int a[600][600];
  int color[600][600];
  vector<pair<pair<int, int>, pair<int, int>>> ans;
  int n = 0;
  int odd = 0;
  bool err = 0;
  int nx = 1;
  int ny = 1;
  bool abc = 0;
  cin >> h >> w;

  for (int i = 1; i <= h; i++)
    for (int j = 1; j <= w; j++) {
      cin >> a[i][j];
      if (a[i][j] % 2 != 0)
        odd++;
    }
  odd /= 2;
  int i = 1, j = 1;
  int ca = 1;
  while (1) {
    if ((i == h && j == w && ca == 1) || (i == h && j == 1 && ca == -1))
      break;
    int pi = i, pj = j;
    if (j == w && ca == 1) {
      ca = (-1);
      i++;
    } else if (j == 1 && i != 1) {
      ca = 1;
      i++;
    } else
      j += ca;
    // cout<<i<<" "<<j<<endl;
    if (a[pi][pj] % 2 != 0) {
      a[i][j]++;
      a[pi][pj]--;
      n++;
      ans.pb(mp(mp(pi, pj), mp(i, j)));
    }
  }
  cout << n << endl;
  for (int i = 0; i < siz(ans); i++)
    cout << ans[i].fi.fi << " " << ans[i].fi.se << " " << ans[i].se.fi << " "
         << ans[i].se.se << endl;
  //-------------------------------
  return 0;
}
//---------------------------------------------------------------------------


Fixed submission:
//  Created by conan1024hao in 2019.
//  Copyright © 2019 conan1024hao. All rights reserved.
//  専用ライブラリです、自由にコピーして構いません。
//  感谢看我的代码！Wechat:conan1024hao QQ:810396815
#pragma GCC optimize("O3")
#include <algorithm>
#include <cctype>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <deque>
#include <iomanip>
#include <iostream>
#include <istream>
#include <iterator>
#include <list>
#include <map>
#include <ostream>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <utility>
#include <vector>
#define INF 10e16
#define MOD 1000000007
#define rep(i, a, n) for (ll i = a; i < (ll)(n); i++)
#define fi first
#define se second
#define pb push_back
#define mp make_pair
#define eb emplace_back
#define mmax(x, y) (x > y ? x : y)
#define mmin(x, y) (x < y ? x : y)
#define chmax(x, y) x = mmax(x, y)
#define chmin(x, y) x = mmin(x, y)
#define all(x) (x).begin(), (x).end()
#define siz(x) (ll)(x).size()
#define PI acos(-1.0)
using namespace std;
typedef long long int ll;
typedef pair<ll, ll> P;
long long GCD(long long a, long long b) { return b ? GCD(b, a % b) : a; }
long long LCM(long long a, long long b) { return a / GCD(a, b) * b; }
int dx[4] = {1, 0, -1, 0};
int dy[4] = {0, 1, 0, -1};
ll cmp(pair<ll, string> a, pair<ll, string> b) {
  if (a.fi != b.fi)
    return a.fi < b.fi;
  else
    return a.se < b.se;
}

//---------------------------------------------------------------------------

//---------------------------------------------------------------------------
int main() { // 問題をちゃんと見ろ!!!!!!!!!!!!!!!!!      llか??????????
  cin.tie(0);
  ios::sync_with_stdio(false);
  //-------------------------------
  int h, w;
  int a[600][600];
  int color[600][600];
  vector<pair<pair<int, int>, pair<int, int>>> ans;
  int n = 0;
  int odd = 0;
  bool err = 0;
  int nx = 1;
  int ny = 1;
  bool abc = 0;
  cin >> h >> w;

  for (int i = 1; i <= h; i++)
    for (int j = 1; j <= w; j++) {
      cin >> a[i][j];
      if (a[i][j] % 2 != 0)
        odd++;
    }
  odd /= 2;
  int i = 1, j = 1;
  int ca = 1;
  while (1) {
    if ((i == h && j == w && ca == 1) || (i == h && j == 1 && ca == -1))
      break;
    int pi = i, pj = j;
    if (j == w && ca == 1) {
      ca = (-1);
      i++;
    } else if (j == 1 && ca == -1) {
      ca = 1;
      i++;
    } else
      j += ca;
    // cout<<i<<" "<<j<<endl;
    if (a[pi][pj] % 2 != 0) {
      a[i][j]++;
      a[pi][pj]--;
      n++;
      ans.pb(mp(mp(pi, pj), mp(i, j)));
    }
  }
  cout << n << endl;
  for (int i = 0; i < siz(ans); i++)
    cout << ans[i].fi.fi << " " << ans[i].fi.se << " " << ans[i].se.fi << " "
         << ans[i].se.se << endl;
  //-------------------------------
  return 0;
}
//---------------------------------------------------------------------------