Problem p03150 (C++)

Buggy submission (status: Runtime Error):
/**
 * code generated by JHelper
 * More info: https://github.com/AlexeyDmitriev/JHelper
 * @author aryssoncf
 */

// Taken from:
// https://github.com/bqi343/USACO/blob/master/Implementations/content/contest/templateShort.cpp

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> pii;
typedef vector<int> vi;
typedef vector<ull> vul;
typedef vector<ll> vl;
typedef vector<pii> vpii;

#define FOR(i, a, b) for (int i = (a); i < (b); ++i)
#define F0R(i, a) FOR(i, 0, a)
#define ROF(i, a, b) for (int i = (b)-1; i >= (a); --i)
#define R0F(i, a) ROF(i, 0, a)
#define trav(a, x) for (auto &a : x)

#define sz(x) (int)x.size()
#define all(x) begin(x), end(x)
#define rsz resize

#define mp make_pair
#define pb push_back
#define f first
#define s second

const int MOD = 1e9 + 7; // 998244353; // = (119<<23)+1
const int MX = 2e5 + 5;

template <class T> bool ckmin(T &a, const T &b) { return a > b ? a = b, 1 : 0; }

template <class T> bool ckmax(T &a, const T &b) { return a < b ? a = b, 1 : 0; }

mt19937 rng((uint32_t)chrono::steady_clock::now().time_since_epoch().count());

//
// Created by aryssoncf on 28/10/2019.
//

#include <type_traits>

#include <iterator>
#include <utility>

template <typename T>
constexpr auto hasBegin(int) -> decltype(std::begin(std::declval<T>()), true) {
  return true;
}

constexpr bool hasBegin(...) { return false; }

template <typename T>
using IsContainer = std::integral_constant<bool, hasBegin<T>(0)>;

#ifndef JHELPER_EXAMPLE_PROJECT_IO_HPP
#define JHELPER_EXAMPLE_PROJECT_IO_HPP

#endif // JHELPER_EXAMPLE_PROJECT_IO_HPP

template <typename T>
std::istream &operator>>(std::istream &is, std::vector<T> &vec) {
  for (T &element : vec) {
    is >> element;
  }
  return is;
}

template <typename T, typename U>
std::istream &operator>>(std::istream &is, std::pair<T, U> &p) {
  is >> p.first;
  is >> p.second;
  return is;
}

template <class X, class Y>
std::ostream &operator<<(std::ostream &os, std::pair<X, Y> const &p) {
  return os << p.first << " " << p.second;
}

template <class Ch, class Tr, class Container>
std::basic_ostream<Ch, Tr> &operator<<(std::basic_ostream<Ch, Tr> &os,
                                       Container const &x) {
  bool first = true;
  for (auto &y : x) {
    if (first) {
      first = false;
    } else {
      os << " ";
    }
    os << y;
  }
  return os;
}

using namespace std;

class BKEYENCEString {

  const string KEYENCE = "keyence";

public:
  void solve(std::istream &in, std::ostream &out) {
    string str;
    in >> str;
    bool res = false;
    int n = sz(str);
    FOR(i, 0, n - 6) {
      int j = n - 7 + i;
      if (str.substr(0, i) + str.substr(j) == KEYENCE) {
        res = true;
      }
    }
    out << (res ? "YES" : "NO") << '\n';
  }

  void setup() {}
};

int main() {
  std::ios_base::sync_with_stdio(false);
  BKEYENCEString solver;
  solver.setup();
  std::istream &in(std::cin);
  std::ostream &out(std::cout);
  in.tie(nullptr);
  out << std::fixed;
  out.precision(20);
  solver.solve(in, out);
  return 0;
}


Fixed submission:
/**
 * code generated by JHelper
 * More info: https://github.com/AlexeyDmitriev/JHelper
 * @author aryssoncf
 */

// Taken from:
// https://github.com/bqi343/USACO/blob/master/Implementations/content/contest/templateShort.cpp

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> pii;
typedef vector<int> vi;
typedef vector<ull> vul;
typedef vector<ll> vl;
typedef vector<pii> vpii;

#define FOR(i, a, b) for (int i = (a); i < (b); ++i)
#define F0R(i, a) FOR(i, 0, a)
#define ROF(i, a, b) for (int i = (b)-1; i >= (a); --i)
#define R0F(i, a) ROF(i, 0, a)
#define trav(a, x) for (auto &a : x)

#define sz(x) (int)x.size()
#define all(x) begin(x), end(x)
#define rsz resize

#define mp make_pair
#define pb push_back
#define f first
#define s second

const int MOD = 1e9 + 7; // 998244353; // = (119<<23)+1
const int MX = 2e5 + 5;

template <class T> bool ckmin(T &a, const T &b) { return a > b ? a = b, 1 : 0; }

template <class T> bool ckmax(T &a, const T &b) { return a < b ? a = b, 1 : 0; }

mt19937 rng((uint32_t)chrono::steady_clock::now().time_since_epoch().count());

//
// Created by aryssoncf on 28/10/2019.
//

#include <type_traits>

#include <iterator>
#include <utility>

template <typename T>
constexpr auto hasBegin(int) -> decltype(std::begin(std::declval<T>()), true) {
  return true;
}

constexpr bool hasBegin(...) { return false; }

template <typename T>
using IsContainer = std::integral_constant<bool, hasBegin<T>(0)>;

#ifndef JHELPER_EXAMPLE_PROJECT_IO_HPP
#define JHELPER_EXAMPLE_PROJECT_IO_HPP

#endif // JHELPER_EXAMPLE_PROJECT_IO_HPP

template <typename T>
std::istream &operator>>(std::istream &is, std::vector<T> &vec) {
  for (T &element : vec) {
    is >> element;
  }
  return is;
}

template <typename T, typename U>
std::istream &operator>>(std::istream &is, std::pair<T, U> &p) {
  is >> p.first;
  is >> p.second;
  return is;
}

template <class X, class Y>
std::ostream &operator<<(std::ostream &os, std::pair<X, Y> const &p) {
  return os << p.first << " " << p.second;
}

template <class Ch, class Tr, class Container>
std::basic_ostream<Ch, Tr> &operator<<(std::basic_ostream<Ch, Tr> &os,
                                       Container const &x) {
  bool first = true;
  for (auto &y : x) {
    if (first) {
      first = false;
    } else {
      os << " ";
    }
    os << y;
  }
  return os;
}

using namespace std;

class BKEYENCEString {

  const string KEYENCE = "keyence";

public:
  void solve(std::istream &in, std::ostream &out) {
    string str;
    in >> str;
    bool res = false;
    int n = sz(str);
    FOR(i, 0, 7) {
      int j = n - 7 + i;
      if (str.substr(0, i) + str.substr(j) == KEYENCE) {
        res = true;
      }
    }
    out << (res ? "YES" : "NO") << '\n';
  }

  void setup() {}
};

int main() {
  std::ios_base::sync_with_stdio(false);
  BKEYENCEString solver;
  solver.setup();
  std::istream &in(std::cin);
  std::ostream &out(std::cout);
  in.tie(nullptr);
  out << std::fixed;
  out.precision(20);
  solver.solve(in, out);
  return 0;
}