Problem p02648 (C++) — buggy submission, verdict: Time Limit Exceeded

#include <bits/stdc++.h>

using namespace std;

using ll = int64_t;
// using ll = long long;
using ull = uint64_t;
using i32 = int32_t;
using u32 = uint32_t;
using i64 = int64_t;
using u64 = uint64_t;
using f64 = double;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
using ld = double;

#define X first
#define Y second

#ifndef ONLINE_JUDGE
#define FWRITE
#endif

namespace io {

#ifndef FWRITE
#include <unistd.h>
auto unistd_read = read;
auto unistd_write = write;
#endif
const int BUFSIZE = 1 << 20;

int isize, osize;
char ibuf[BUFSIZE + 10], obuf[BUFSIZE + 10];
char *is, *it, *os = obuf, *ot = obuf + BUFSIZE;

char getchar() {
  if (is == it) {
    is = ibuf;
#ifdef FWRITE
    it = ibuf + fread(ibuf, 1, BUFSIZE, stdin);
#else
    it = ibuf + unistd_read(STDIN_FILENO, ibuf, BUFSIZE);
#endif
    if (is == it)
      return EOF;
  }
  return *is++;
}

char getalpha() {
  char c = getchar();
  while (!isalpha(c))
    c = getchar();
  return c;
}

void putchar(char c) {
  *os++ = c;
  if (os == ot) {
#ifdef FWRITE
    fwrite(obuf, 1, BUFSIZE, stdout);
#else
    unistd_write(STDOUT_FILENO, obuf, BUFSIZE);
#endif
    os = obuf;
  }
}

int inp() {
  int x = 0, f = 0;
  char ch;
  for (ch = getchar(); !isdigit(ch); ch = getchar()) {
    if (ch == EOF)
      return -1;
    if (ch == '-')
      f = 1;
  }
  for (; isdigit(ch); x = x * 10 + ch - '0', ch = getchar())
    ;
  return f ? -x : x;
}

ll inp_ll() {
  ll x = 0;
  int f = 0;
  char ch;
  for (ch = getchar(); !isdigit(ch); ch = getchar())
    if (ch == '-')
      f = 1;
  for (; isdigit(ch); x = x * 10 + ch - '0', ch = getchar())
    ;
  return f ? -x : x;
}

template <class T> bool read(T &x) {
  x = 0;
  int f = 0;
  char ch;
  for (ch = getchar(); !isdigit(ch); ch = getchar()) {
    if (ch == EOF)
      return 0;
    if (ch == '-')
      f = 1;
  }
  for (; isdigit(ch); x = x * 10 + ch - '0', ch = getchar())
    ;
  if (f)
    x = -x;
  return 1;
}

bool read(char *s) {
  char *t = s;
  char ch = getchar();
  for (; ch == ' ' || ch == '\\n'; ch = getchar())
    ;
  for (; ch != ' ' && ch != '\\n' && ch != EOF; ch = getchar())
    *t++ = ch;
  *t = 0;
  return s != t;
}

template <class T, class... Args> bool read(T &x, Args &...args) {
  return read(x) && read(args...);
}

template <class T> bool readln(T &x) {
  x = 0;
  int f = 0;
  char ch;
  for (ch = getchar(); !isdigit(ch); ch = getchar()) {
    if (ch == EOF)
      return 0;
    if (ch == '-')
      f = 1;
  }
  for (; isdigit(ch); x = x * 10 + ch - '0', ch = getchar())
    ;
  if (f)
    x = -x;
  for (; ch != '\\n' && ch != EOF; ch = getchar())
    ;
  return 1;
}

bool readln(char *s) {
  char *t = s;
  while (1) {
    char ch = getchar();
    if (ch == '\\n' || ch == EOF)
      break;
    *t++ = ch;
  }
  *t = 0;
  return s != t;
}

template <class T, class... Args> bool readln(T &x, Args &...args) {
  return read(x) && readln(args...);
}

template <class T> void write(T x) {
  static char s[22];
  static char *it = s + 20;
  static char *end = s + 20;

  if (x < 0) {
    putchar('-');
    x = -x;
  }

  do {
    *--it = x % 10 + '0';
    x /= 10;
  } while (x);
  /*
  if (!x)
          *-- it = '0';
  while (x)
  {
          *-- it = x%10+'0';
          x /= 10;
  }
  */
  for (; it < end; ++it)
    putchar(*it);
}

void write(const char *s) {
  for (; *s; ++s)
    putchar(*s);
}

template <> void write(char *s) { write((const char *)s); }

template <> void write(char c) { putchar(c); }

template <class T, class... Args> void write(T x, Args... args) {
  write(x);
  write(args...);
}

void writeln() { putchar('\\n'); }

template <class T, class... Args> void writeln(T x, Args... args) {
  write(x);
  writeln(args...);
}

template <class Iterator> bool input(Iterator st, Iterator ed) {
  for (; st != ed; ++st) {
    if (!read(*st))
      return false;
  }
  return true;
}

template <class T> bool input(T &a) { return input(a.begin(), a.end()); }

template <class Iterator>
void print(Iterator st, Iterator ed, const char *c = " ") {
  int flag = 0;
  for (; st != ed; ++st) {
    if (flag)
      write(c);
    flag = 1;
    write(*st);
  }
  writeln();
}

template <class T> void print(const T &a, const char *c = " ") {
  print(a.begin(), a.end(), c);
}

struct ender {
  ~ender() {
    if (os != obuf)
#ifdef FWRITE
      fwrite(obuf, 1, os - obuf, stdout);
#else
      unistd_write(STDOUT_FILENO, obuf, os - obuf);
#endif
  }
} __ender;

} // namespace io

int64_t power(int64_t a, int64_t b, int64_t p) {
  if (!b)
    return 1;
  int64_t t = power(a, b >> 1, p);
  t = t * t % p;
  if (b & 1)
    t = t * a % p;
  return t;
}

// mt19937_64 rd(chrono::steady_clock::now().time_since_epoch().count());
mt19937 rd(chrono::steady_clock::now().time_since_epoch().count());

using namespace io;

template <class T> inline void freshmin(T &a, const T &b) {
  if (a > b)
    a = b;
}

template <class T> inline void freshmax(T &a, const T &b) {
  if (a < b)
    a = b;
}

const ll B = 31;
const ll MOD = 998244353;
const int INF = 1000000010;
const ll INFll = 4000000000000000000LL;
const int MAXN = 500010;

// int dx[] = { -1, 1, 0, 0, -1, -1, 1, 1 };
// int dy[] = { 0, 0, -1, 1, -1, 1, -1, 1 };

ld det(ld x1, ld y1, ld x2, ld y2, ld x3, ld y3) {
  return x1 * y2 - x2 * y1 + x2 * y3 - x3 * y2 + x3 * y1 - x1 * y3;
}

int N, Q;
int V[MAXN], W[MAXN];

int sV[MAXN], sW[MAXN], tV[MAXN], tW[MAXN];

pii can[MAXN];
vector<pii> tmp[MAXN];

void solve() {
  N = inp();
  for (int i = 1; i <= N; ++i) {
    W[i] = inp();
    V[i] = inp();
  }

  for (int x = 1; x <= N; ++x) {
    vector<int> a;
    for (int tx = x; tx; tx /= 2)
      a.push_back(tx);
    if (a.size() > 9)
      continue;
    int n = a.size();
    for (int s = 1; s < 1 << n; ++s) {
      int id = __builtin_ctz(s);
      sV[s] = sV[s ^ (1 << id)] + V[a[id]];
      sW[s] = sW[s ^ (1 << id)] + W[a[id]];
      can[s] = {sV[s], sW[s]};
    }
    sort(can, can + (1 << n), [](const pii &a, const pii &b) {
      return a.first < b.first || a.first == b.first && a.second > b.second;
    });
    int cur = 0;
    for (int s = 1; s < 1 << n; ++s) {
      if (can[cur].second < can[s].second) {
        ++cur;
        can[cur] = can[s];
      }
    }
    tmp[x] = vector<pii>(can, can + cur + 1);
  }

  Q = inp();
  while (Q--) {
    int x = inp(), L = inp();
    vector<int> a;
    for (; x; x /= 2)
      a.push_back(x);
    int len = a.size();
    int n = min(len, 9);
    int m = len - n;

    int ans = 0;
    x = a[m];

    for (auto [sv, sw] : tmp[x]) {
      if (sv <= L)
        freshmax(ans, sw);
    }

    for (int s = 1; s < 1 << m; ++s) {
      int id = __builtin_ctz(s);
      tV[s] = tV[s ^ (1 << id)] + V[a[id]];
      tW[s] = tW[s ^ (1 << id)] + W[a[id]];
      int remain = L - tV[s];
      if (remain >= 0) {
        auto pos =
            upper_bound(tmp[x].begin(), tmp[x].end(), pii(remain + 1, 0));
        pos--;
        freshmax(ans, pos->second + tW[s]);
      }
    }

    writeln(ans);
  }
}

int main() {

  int T = 1;
  // read(T);
  for (int test = 1; test <= T; ++test) {
    // write("Case #", test, ": ");
    solve();
  }

  return 0;
}

Error: TLE

Fixed submission:

#include <bits/stdc++.h>

using namespace std;

using ll = int64_t;
// using ll = long long;
using ull = uint64_t;
using i32 = int32_t;
using u32 = uint32_t;
using i64 = int64_t;
using u64 = uint64_t;
using f64 = double;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
using ld = double;

#define X first
#define Y second

#ifndef ONLINE_JUDGE
#define FWRITE
#endif

namespace io {

#ifndef FWRITE
#include <unistd.h>
auto unistd_read = read;
auto unistd_write = write;
#endif
const int BUFSIZE = 1 << 20;

int isize, osize;
char ibuf[BUFSIZE + 10], obuf[BUFSIZE + 10];
char *is, *it, *os = obuf, *ot = obuf + BUFSIZE;

char getchar() {
  if (is == it) {
    is = ibuf;
#ifdef FWRITE
    it = ibuf + fread(ibuf, 1, BUFSIZE, stdin);
#else
    it = ibuf + unistd_read(STDIN_FILENO, ibuf, BUFSIZE);
#endif
    if (is == it)
      return EOF;
  }
  return *is++;
}

char getalpha() {
  char c = getchar();
  while (!isalpha(c))
    c = getchar();
  return c;
}

void putchar(char c) {
  *os++ = c;
  if (os == ot) {
#ifdef FWRITE
    fwrite(obuf, 1, BUFSIZE, stdout);
#else
    unistd_write(STDOUT_FILENO, obuf, BUFSIZE);
#endif
    os = obuf;
  }
}

int inp() {
  int x = 0, f = 0;
  char ch;
  for (ch = getchar(); !isdigit(ch); ch = getchar()) {
    if (ch == EOF)
      return -1;
    if (ch == '-')
      f = 1;
  }
  for (; isdigit(ch); x = x * 10 + ch - '0', ch = getchar())
    ;
  return f ? -x : x;
}

ll inp_ll() {
  ll x = 0;
  int f = 0;
  char ch;
  for (ch = getchar(); !isdigit(ch); ch = getchar())
    if (ch == '-')
      f = 1;
  for (; isdigit(ch); x = x * 10 + ch - '0', ch = getchar())
    ;
  return f ? -x : x;
}

template <class T> bool read(T &x) {
  x = 0;
  int f = 0;
  char ch;
  for (ch = getchar(); !isdigit(ch); ch = getchar()) {
    if (ch == EOF)
      return 0;
    if (ch == '-')
      f = 1;
  }
  for (; isdigit(ch); x = x * 10 + ch - '0', ch = getchar())
    ;
  if (f)
    x = -x;
  return 1;
}

bool read(char *s) {
  char *t = s;
  char ch = getchar();
  for (; ch == ' ' || ch == '\\n'; ch = getchar())
    ;
  for (; ch != ' ' && ch != '\\n' && ch != EOF; ch = getchar())
    *t++ = ch;
  *t = 0;
  return s != t;
}

template <class T, class... Args> bool read(T &x, Args &...args) {
  return read(x) && read(args...);
}

template <class T> bool readln(T &x) {
  x = 0;
  int f = 0;
  char ch;
  for (ch = getchar(); !isdigit(ch); ch = getchar()) {
    if (ch == EOF)
      return 0;
    if (ch == '-')
      f = 1;
  }
  for (; isdigit(ch); x = x * 10 + ch - '0', ch = getchar())
    ;
  if (f)
    x = -x;
  for (; ch != '\\n' && ch != EOF; ch = getchar())
    ;
  return 1;
}

bool readln(char *s) {
  char *t = s;
  while (1) {
    char ch = getchar();
    if (ch == '\\n' || ch == EOF)
      break;
    *t++ = ch;
  }
  *t = 0;
  return s != t;
}

template <class T, class... Args> bool readln(T &x, Args &...args) {
  return read(x) && readln(args...);
}

template <class T> void write(T x) {
  static char s[22];
  static char *it = s + 20;
  static char *end = s + 20;

  if (x < 0) {
    putchar('-');
    x = -x;
  }

  do {
    *--it = x % 10 + '0';
    x /= 10;
  } while (x);
  /*
  if (!x)
          *-- it = '0';
  while (x)
  {
          *-- it = x%10+'0';
          x /= 10;
  }
  */
  for (; it < end; ++it)
    putchar(*it);
}

void write(const char *s) {
  for (; *s; ++s)
    putchar(*s);
}

template <> void write(char *s) { write((const char *)s); }

template <> void write(char c) { putchar(c); }

template <class T, class... Args> void write(T x, Args... args) {
  write(x);
  write(args...);
}

void writeln() { putchar('\\n'); }

template <class T, class... Args> void writeln(T x, Args... args) {
  write(x);
  writeln(args...);
}

template <class Iterator> bool input(Iterator st, Iterator ed) {
  for (; st != ed; ++st) {
    if (!read(*st))
      return false;
  }
  return true;
}

template <class T> bool input(T &a) { return input(a.begin(), a.end()); }

template <class Iterator>
void print(Iterator st, Iterator ed, const char *c = " ") {
  int flag = 0;
  for (; st != ed; ++st) {
    if (flag)
      write(c);
    flag = 1;
    write(*st);
  }
  writeln();
}

template <class T> void print(const T &a, const char *c = " ") {
  print(a.begin(), a.end(), c);
}

struct ender {
  ~ender() {
    if (os != obuf)
#ifdef FWRITE
      fwrite(obuf, 1, os - obuf, stdout);
#else
      unistd_write(STDOUT_FILENO, obuf, os - obuf);
#endif
  }
} __ender;

} // namespace io

int64_t power(int64_t a, int64_t b, int64_t p) {
  if (!b)
    return 1;
  int64_t t = power(a, b >> 1, p);
  t = t * t % p;
  if (b & 1)
    t = t * a % p;
  return t;
}

// mt19937_64 rd(chrono::steady_clock::now().time_since_epoch().count());
mt19937 rd(chrono::steady_clock::now().time_since_epoch().count());

using namespace io;

template <class T> inline void freshmin(T &a, const T &b) {
  if (a > b)
    a = b;
}

template <class T> inline void freshmax(T &a, const T &b) {
  if (a < b)
    a = b;
}

const ll B = 31;
const ll MOD = 998244353;
const int INF = 1000000010;
const ll INFll = 4000000000000000000LL;
const int MAXN = 500010;

// int dx[] = { -1, 1, 0, 0, -1, -1, 1, 1 };
// int dy[] = { 0, 0, -1, 1, -1, 1, -1, 1 };

ld det(ld x1, ld y1, ld x2, ld y2, ld x3, ld y3) {
  return x1 * y2 - x2 * y1 + x2 * y3 - x3 * y2 + x3 * y1 - x1 * y3;
}

int N, Q;
int V[MAXN], W[MAXN];

int sV[MAXN], sW[MAXN], tV[MAXN], tW[MAXN];

pii can[MAXN];

void solve() {
  N = inp();
  for (int i = 1; i <= N; ++i) {
    W[i] = inp();
    V[i] = inp();
  }
  /*
  for (int x = 1; x <= N; ++x)
  {
          vector<int> a;
          for (; x; x /= 2) a.push_back(x);
          if (a.size() > 9) continue;
  }
  */
  Q = inp();
  while (Q--) {
    int x = inp(), L = inp();
    vector<int> a;
    for (; x; x /= 2)
      a.push_back(x);
    int len = a.size();
    int n = len / 2;
    int m = len - n;
    can[0] = {0, 0};

    int ans = 0;
    for (int s = 1; s < 1 << n; ++s) {
      int id = __builtin_ctz(s);
      sV[s] = sV[s ^ (1 << id)] + V[a[id]];
      sW[s] = sW[s ^ (1 << id)] + W[a[id]];
      can[s] = {sV[s], sW[s]};
      if (sV[s] <= L)
        freshmax(ans, sW[s]);
    }
    sort(can, can + (1 << n), [](const pii &a, const pii &b) {
      return a.first < b.first || a.first == b.first && a.second > b.second;
    });
    int cur = 0;
    for (int s = 1; s < 1 << n; ++s) {
      if (can[cur].second < can[s].second) {
        ++cur;
        can[cur] = can[s];
      }
    }

    for (int s = 1; s < 1 << m; ++s) {
      int id = __builtin_ctz(s);
      tV[s] = tV[s ^ (1 << id)] + V[a[n + id]];
      tW[s] = tW[s ^ (1 << id)] + W[a[n + id]];
      int remain = L - tV[s];
      if (remain >= 0) {
        auto pos =
            upper_bound(can, can + cur + 1, pii(remain + 1, 0)) - can - 1;
        freshmax(ans, can[pos].second + tW[s]);
      }
    }

    writeln(ans);
  }
}

int main() {

  int T = 1;
  // read(T);
  for (int test = 1; test <= T; ++test) {
    // write("Case #", test, ": ");
    solve();
  }

  return 0;
}