Problem p02603 (C++) — buggy submission, verdict: Time Limit Exceeded

/*
このコード、と～おれ!
Be accepted!
∧＿∧　
（｡･ω･｡)つ━☆・*。
⊂　　 ノ 　　　・゜+.
　しーＪ　　　°。+ *´¨)
 　　　　　　　　　.· ´¸.·*´¨) ¸.·*¨)
                  　　　　　　　　　　(¸.·´ (¸.·'* ☆
*/

#include <algorithm>
#include <bitset>
#include <cassert>
#include <cmath>
#include <complex>
#include <cstdio>
#include <cstring>
#include <functional>
#include <iomanip>
#include <iostream>
#include <list>
#include <map>
#include <numeric>
#include <queue>
#include <random>
#include <regex>
#include <set>
#include <stack>
#include <string>
#include <unordered_map>
#include <vector>

////多倍長整数, cpp_intで宣言
// #include <boost/multiprecision/cpp_int.hpp>
// using namespace boost::multiprecision;

// #pragma gcc target ("avx2")
// #pragma gcc optimization ("Ofast")
// #pragma gcc optimization ("unroll-loops")
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define rep1(i, n) for (int i = 1; i <= (n); ++i)
#define rep2(i, n) for (int i = 2; i < (n); ++i)
#define repr(i, n) for (int i = n; i >= 0; --i)
#define reprm(i, n) for (int i = n - 1; i >= 0; --i)
#define printynl(a) printf(a ? "yes\\n" : "no\\n")
#define printyn(a) printf(a ? "Yes\\n" : "No\\n")
#define printYN(a) printf(a ? "YES\\n" : "NO\\n")
#define printim(a) printf(a ? "possible\\n" : "imposible\\n")
#define printdb(a) printf("%.50lf\\n", a)    // 少数出力
#define printLdb(a) printf("%.50Lf\\n", a)   // 少数出力
#define printdbd(a) printf("%.16lf\\n", a)   // 少数出力(桁少なめ)
#define prints(s) printf("%s\\n", s.c_str()) // string出力
#define all(x) (x).begin(), (x).end()
#define deg_to_rad(deg) (((deg) / 360.0L) * 2.0L * PI)
#define rad_to_deg(rad) (((rad) / 2.0L / PI) * 360.0L)
#define Please return
#define AC 0
#define manhattan_dist(a, b, c, d)                                             \\
  (abs(a - c) + abs(b - d)) /*(a, b) から (c, d) のマンハッタン距離 */
#define inf numeric_limits<double>::infinity();
#define linf numeric_limits<long double>::infinity()

using ll = long long;
using ull = unsigned long long;

constexpr int INF = 1073741823;
constexpr int MINF = -1073741823;
constexpr ll LINF = ll(4661686018427387903);
constexpr ll MOD = 1e9 + 7;
constexpr long double eps = 1e-6;
const long double PI = acosl(-1.0L);

using namespace std;

void scans(string &str) {
  char c;
  str = "";
  scanf("%c", &c);
  if (c == '\\n')
    scanf("%c", &c);
  while (c != '\\n' && c != -1 && c != ' ') {
    str += c;
    scanf("%c", &c);
  }
}

void scanc(char &str) {
  char c;
  scanf("%c", &c);
  if (c == -1)
    return;
  while (c == '\\n') {
    scanf("%c", &c);
  }
  str = c;
}

double acot(double x) { return PI / 2 - atan(x); }

ll LSB(ll n) { return (n & (-n)); }

/*-----------------------------------------ここからコード-----------------------------------------*/

int main() {

  int n;
  scanf("%d", &n);
  vector<ll> a(n);
  rep(i, n) scanf("%lld", &a[i]);
  a.erase(unique(all(a)), a.end());
  n = a.size();
  ll money = 1000, kabu = 0, ans = 0;
  rep(i, n) {
    if (i == 0) {
      if (a[i] < a[i + 1]) {
        kabu += money / a[i];
        money -= money / a[i] * a[i];
      }
    } else if (i == n - 1) {
      money += kabu * a[i];
      kabu = 0;
      ans = max(ans, money);
    } else {
      if (a[i - 1] < a[i] and a[i] > a[i + 1]) {
        money += kabu * a[i];
        kabu = 0;
      } else if (a[i - 1] > a[i] and a[i] < a[i + 1]) {
        kabu += money / a[i];
        money -= money / a[i] * a[i];
      }
    }
    ans = max(ans, money + kabu * a[n - 1]);
  }
  printf("%lld\\n", ans);

  Please AC;
}

Error: TLE

Fixed submission:

/*
このコード、と～おれ!
Be accepted!
∧＿∧　
（｡･ω･｡)つ━☆・*。
⊂　　 ノ 　　　・゜+.
　しーＪ　　　°。+ *´¨)
 　　　　　　　　　.· ´¸.·*´¨) ¸.·*¨)
                  　　　　　　　　　　(¸.·´ (¸.·'* ☆
*/

#include <algorithm>
#include <bitset>
#include <cassert>
#include <cmath>
#include <complex>
#include <cstdio>
#include <cstring>
#include <functional>
#include <iomanip>
#include <iostream>
#include <list>
#include <map>
#include <numeric>
#include <queue>
#include <random>
#include <regex>
#include <set>
#include <stack>
#include <string>
#include <unordered_map>
#include <vector>

////多倍長整数, cpp_intで宣言
// #include <boost/multiprecision/cpp_int.hpp>
// using namespace boost::multiprecision;

// #pragma gcc target ("avx2")
// #pragma gcc optimization ("Ofast")
// #pragma gcc optimization ("unroll-loops")
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define rep1(i, n) for (int i = 1; i <= (n); ++i)
#define rep2(i, n) for (int i = 2; i < (n); ++i)
#define repr(i, n) for (int i = n; i >= 0; --i)
#define reprm(i, n) for (int i = n - 1; i >= 0; --i)
#define printynl(a) printf(a ? "yes\\n" : "no\\n")
#define printyn(a) printf(a ? "Yes\\n" : "No\\n")
#define printYN(a) printf(a ? "YES\\n" : "NO\\n")
#define printim(a) printf(a ? "possible\\n" : "imposible\\n")
#define printdb(a) printf("%.50lf\\n", a)    // 少数出力
#define printLdb(a) printf("%.50Lf\\n", a)   // 少数出力
#define printdbd(a) printf("%.16lf\\n", a)   // 少数出力(桁少なめ)
#define prints(s) printf("%s\\n", s.c_str()) // string出力
#define all(x) (x).begin(), (x).end()
#define deg_to_rad(deg) (((deg) / 360.0L) * 2.0L * PI)
#define rad_to_deg(rad) (((rad) / 2.0L / PI) * 360.0L)
#define Please return
#define AC 0
#define manhattan_dist(a, b, c, d)                                             \\
  (abs(a - c) + abs(b - d)) /*(a, b) から (c, d) のマンハッタン距離 */
#define inf numeric_limits<double>::infinity();
#define linf numeric_limits<long double>::infinity()

using ll = long long;
using ull = unsigned long long;

constexpr int INF = 1073741823;
constexpr int MINF = -1073741823;
constexpr ll LINF = ll(4661686018427387903);
constexpr ll MOD = 1e9 + 7;
constexpr long double eps = 1e-6;
const long double PI = acosl(-1.0L);

using namespace std;

void scans(string &str) {
  char c;
  str = "";
  scanf("%c", &c);
  if (c == '\\n')
    scanf("%c", &c);
  while (c != '\\n' && c != -1 && c != ' ') {
    str += c;
    scanf("%c", &c);
  }
}

void scanc(char &str) {
  char c;
  scanf("%c", &c);
  if (c == -1)
    return;
  while (c == '\\n') {
    scanf("%c", &c);
  }
  str = c;
}

double acot(double x) { return PI / 2 - atan(x); }

ll LSB(ll n) { return (n & (-n)); }

/*-----------------------------------------ここからコード-----------------------------------------*/

void dfs(const int &n, const vector<int> &a, const int &money, const int &kabu,
         const int &day, int &ans) {
  if (day == n) {
    ans = max(ans, money);
  } else {
    for (int i = 0; money - a[day] * i >= 0; ++i)
      dfs(n, a, money - a[day] * i, kabu + i, day + 1, ans);
    for (int i = 1; kabu - i >= 0; ++i)
      dfs(n, a, money + a[day] * i, kabu - i, day + 1, ans);
  }
}

int main() {

  int n;
  scanf("%d", &n);
  vector<int> a(n);
  rep(i, n) scanf("%d", &a[i]);
  int ans = 0;
  dfs(n, a, 1000, 0, 0, ans);
  printf("%d\\n", ans);

  Please AC;
}