Problem p00017 (C++) — buggy submission, verdict: Time Limit Exceeded

#include <bits/stdc++.h>
using namespace std;

// #define int long long
#define reps(i, s, n) for (int(i) = (s); (i) < (n); ++(i))
#define rep(i, n) reps(i, 0, n)
#define rept(i, n) rep(i, (n) + 1)
#define repst(i, s, n) reps(i, s, (n) + 1)
#define reprt(i, n, t) for (int(i) = (n); (i) >= (t); --(i))
#define repr(i, n) reprt(i, n, 0)
#define each(itr, v) for (auto &(itr) : (v))
#define all(c) (c).begin(), (c).end()
#define rall(c) (c).rbegin(), (c).rend()
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define tmax(x, y, z) max(x, max(y, z))
#define tmin(x, y, z) min(x, min(y, z))
#define chmin(x, y) x = min(x, y)
#define chmax(x, y) x = max(x, y)
#define ln '\\n'
#define bln(i, n) (((i) == (n)-1) ? '\\n' : ' ')
#define dbg(x) cout << #x " = " << (x) << ln << flush
#define dbga(x, n)                                                             \\
  {                                                                            \\
    cout << #x " : ";                                                          \\
    for (int(i) = 0; i < (n); ++i) {                                           \\
      cout << ((x)[i]) << (i == ((n)-1) ? '\\n' : ' ') << flush;                \\
    }                                                                          \\
  }
#define zero(a) memset(a, 0, sizeof(a))
#define unq(a) sort(all(a)), a.erase(unique(all(a)), a.end())

typedef complex<double> P;
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef vector<string> vst;
typedef vector<pii> vpii;
typedef vector<pll> vpll;
typedef vector<vector<int>> mat;

const ll inf = (ll)1e9 + 10;
const ll linf = (ll)1e18 + 10;
const ll mod = (ll)(1e9 + 7);
const int dx[] = {0, 1, 0, -1};
const int dy[] = {1, 0, -1, 0};
const int ddx[] = {0, 1, 1, 1, 0, -1, -1, -1};
const int ddy[] = {1, 1, 0, -1, -1, -1, 0, 1};
const double eps = 1e-10;

ll mop(ll a, ll b, ll m = mod) {
  ll r = 1;
  a %= m;
  for (; b; b >>= 1) {
    if (b & 1)
      r = r * a % m;
    a = a * a % m;
  }
  return r;
}
ll gcd(ll a, ll b) { return b ? gcd(b, a % b) : a; }
ll lcm(ll a, ll b) { return a * b / gcd(a, b); }
bool ool(int x, int y, int h, int w) {
  return ((x < 0) || (h <= x) || (y < 0) || (w <= y));
}
bool deq(double a, double b) { return abs(a - b) < eps; }

struct oreno_initializer {
  oreno_initializer() {
    cin.tie(0);
    ios::sync_with_stdio(0);
  }
} oreno_initializer;

// ━━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…
// .｡.:( ^ω^)・ﾟ＋.｡.:( ^ω^)・ﾟ＋.｡.:( ^ω^)・ﾟ＋.｡.:( ^ω^)・ﾟ＋.｡.:( ^ω^)・ﾟ＋
// ・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・

typedef string::const_iterator S;
string s;

//(t.size()>=3 && t.substr(0,3)=="the") || (t.size()>=4 &&
//(t.substr(0,4)=="that" || t.substr(0,4)=="this"))

bool ok(S &i, S &e) {
  if (i == e)
    return 0;
  string t;
  while (*i != ' ')
    t.pb(*i), i++;
  if (t == "the" || t == "this" || t == "that")
    return 1;
  return ok(++i, e);
}

signed main() {
  while (getline(cin, s)) {
    if (s.empty())
      break;
    s.pb(' ');
    rep(i, 26) {
      S b = s.begin(), c = s.end();
      if (ok(b, c)) {
        cout << s.substr(0, s.size() - 1) << ln << flush;
        break;
      }
      rep(j, s.size()) if ('a' <= s[j] && s[j] <= 'z') {
        s[j]++;
        if (s[j] > 'z')
          s[j] = 'a';
      }
    }
  }
}


Error: TLE

Fixed submission:

#include <bits/stdc++.h>
using namespace std;

// #define int long long
#define reps(i, s, n) for (int(i) = (s); (i) < (n); ++(i))
#define rep(i, n) reps(i, 0, n)
#define rept(i, n) rep(i, (n) + 1)
#define repst(i, s, n) reps(i, s, (n) + 1)
#define reprt(i, n, t) for (int(i) = (n); (i) >= (t); --(i))
#define repr(i, n) reprt(i, n, 0)
#define each(itr, v) for (auto &(itr) : (v))
#define all(c) (c).begin(), (c).end()
#define rall(c) (c).rbegin(), (c).rend()
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define tmax(x, y, z) max(x, max(y, z))
#define tmin(x, y, z) min(x, min(y, z))
#define chmin(x, y) x = min(x, y)
#define chmax(x, y) x = max(x, y)
#define ln '\\n'
#define bln(i, n) (((i) == (n)-1) ? '\\n' : ' ')
#define dbg(x) cout << #x " = " << (x) << ln << flush
#define dbga(x, n)                                                             \\
  {                                                                            \\
    cout << #x " : ";                                                          \\
    for (int(i) = 0; i < (n); ++i) {                                           \\
      cout << ((x)[i]) << (i == ((n)-1) ? '\\n' : ' ') << flush;                \\
    }                                                                          \\
  }
#define zero(a) memset(a, 0, sizeof(a))
#define unq(a) sort(all(a)), a.erase(unique(all(a)), a.end())

typedef complex<double> P;
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef vector<string> vst;
typedef vector<pii> vpii;
typedef vector<pll> vpll;
typedef vector<vector<int>> mat;

const ll inf = (ll)1e9 + 10;
const ll linf = (ll)1e18 + 10;
const ll mod = (ll)(1e9 + 7);
const int dx[] = {0, 1, 0, -1};
const int dy[] = {1, 0, -1, 0};
const int ddx[] = {0, 1, 1, 1, 0, -1, -1, -1};
const int ddy[] = {1, 1, 0, -1, -1, -1, 0, 1};
const double eps = 1e-10;

ll mop(ll a, ll b, ll m = mod) {
  ll r = 1;
  a %= m;
  for (; b; b >>= 1) {
    if (b & 1)
      r = r * a % m;
    a = a * a % m;
  }
  return r;
}
ll gcd(ll a, ll b) { return b ? gcd(b, a % b) : a; }
ll lcm(ll a, ll b) { return a * b / gcd(a, b); }
bool ool(int x, int y, int h, int w) {
  return ((x < 0) || (h <= x) || (y < 0) || (w <= y));
}
bool deq(double a, double b) { return abs(a - b) < eps; }

struct oreno_initializer {
  oreno_initializer() {
    cin.tie(0);
    ios::sync_with_stdio(0);
  }
} oreno_initializer;

// ━━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…
// .｡.:( ^ω^)・ﾟ＋.｡.:( ^ω^)・ﾟ＋.｡.:( ^ω^)・ﾟ＋.｡.:( ^ω^)・ﾟ＋.｡.:( ^ω^)・ﾟ＋
// ・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・

typedef string::const_iterator S;
string s;

//(t.size()>=3 && t.substr(0,3)=="the") || (t.size()>=4 &&
//(t.substr(0,4)=="that" || t.substr(0,4)=="this"))

bool ok(S &i, S &e) {
  if (i == e)
    return 0;
  string t;
  while (*i != ' ')
    t.pb(*i), i++;
  if (t == "the" || t == "this" || t == "that")
    return 1;
  return ok(++i, e);
}

signed main() {
  while (1) {
    getline(cin, s);
    s.pb(' ');
    rep(i, 26) {
      S b = s.begin(), c = s.end();
      if (ok(b, c)) {
        cout << s << ln << flush;
        break;
      }
      rep(j, s.size()) if ('a' <= s[j] && s[j] <= 'z') {
        s[j]++;
        if (s[j] > 'z')
          s[j] = 'a';
      }
    }
  }
}