Problem p02721 (C++) — buggy submission, verdict: Runtime Error

#include <bits/stdc++.h>

//    #include <boost/multiprecision/cpp_int.hpp>
#define int long long
#define inf 1000000007
#define pa pair<int, int>
#define ll long long
#define pal pair<double, double>
#define ppap pair<pa, int>
#define PI 3.14159265358979323846
#define paa pair<int, char>
#define mp make_pair
#define pb push_back
#define EPS (1e-8)

int dx[8] = {0, 1, 0, -1, 1, 1, -1, -1};
int dy[8] = {1, 0, -1, 0, -1, 1, 1, -1};
using namespace std;
class pa3 {
public:
  int x;
  int y, z;
  pa3(int x = 0, int y = 0, int z = 0) : x(x), y(y), z(z) {}
  bool operator<(const pa3 &p) const {
    if (x != p.x)
      return x < p.x;
    if (y != p.y)
      return y < p.y;
    return z < p.z;
    // return x != p.x ? x<p.x: y<p.y;
  }
  bool operator>(const pa3 &p) const {
    if (x != p.x)
      return x > p.x;
    if (y != p.y)
      return y > p.y;
    return z > p.z;
    // return x != p.x ? x<p.x: y<p.y;
  }
  bool operator==(const pa3 &p) const {
    return x == p.x && y == p.y && z == p.z;
  }
  bool operator!=(const pa3 &p) const {
    return !(x == p.x && y == p.y && z == p.z);
  }
};

class pa4 {
public:
  int x;
  int y, z, w;
  pa4(int x = 0, int y = 0, int z = 0, int w = 0) : x(x), y(y), z(z), w(w) {}
  bool operator<(const pa4 &p) const {
    if (x != p.x)
      return x < p.x;
    if (y != p.y)
      return y < p.y;
    if (z != p.z)
      return z < p.z;
    return w < p.w;
    // return x != p.x ? x<p.x: y<p.y;
  }
  bool operator>(const pa4 &p) const {
    if (x != p.x)
      return x > p.x;
    if (y != p.y)
      return y > p.y;
    if (z != p.z)
      return z > p.z;
    return w > p.w;
    // return x != p.x ? x<p.x: y<p.y;
  }
  bool operator==(const pa4 &p) const {
    return x == p.x && y == p.y && z == p.z && w == p.w;
  }
};
class pa2 {
public:
  int x, y;
  pa2(int x = 0, int y = 0) : x(x), y(y) {}
  pa2 operator+(pa2 p) { return pa2(x + p.x, y + p.y); }
  pa2 operator-(pa2 p) { return pa2(x - p.x, y - p.y); }
  bool operator<(const pa2 &p) const { return y != p.y ? y < p.y : x < p.x; }
  bool operator>(const pa2 &p) const { return x != p.x ? x < p.x : y < p.y; }
  bool operator==(const pa2 &p) const {
    return abs(x - p.x) == 0 && abs(y - p.y) == 0;
  }
  bool operator!=(const pa2 &p) const {
    return !(abs(x - p.x) == 0 && abs(y - p.y) == 0);
  }
};

string itos(int i) {
  ostringstream s;
  s << i;
  return s.str();
}

int gcd(int v, int b) {
  if (v == 0)
    return b;
  if (b == 0)
    return v;
  if (v > b)
    return gcd(b, v);
  if (v == b)
    return b;
  if (b % v == 0)
    return v;
  return gcd(v, b % v);
}

int mod;
int extgcd(int a, int b, int &x, int &y) {
  if (b == 0) {
    x = 1;
    y = 0;
    return a;
  }
  int d = extgcd(b, a % b, y, x);
  y -= a / b * x;
  return d;
}
pa operator+(const pa &l, const pa &r) {
  return {l.first + r.first, l.second + r.second};
}
pa operator-(const pa &l, const pa &r) {
  return {l.first - r.first, l.second - r.second};
}
int beki(int wa, int rr, int warukazu) {
  if (rr == 0)
    return 1 % warukazu;
  if (rr == 1)
    return wa % warukazu;
  wa %= warukazu;
  if (rr % 2 == 1)
    return ((ll)beki(wa, rr - 1, warukazu) * (ll)wa) % warukazu;
  ll zx = beki(wa, rr / 2, warukazu);
  return (zx * zx) % warukazu;
}

int pr[1000100];
int inv[1000010];

int comb(int nn, int rr) {
  if (rr < 0 || rr > nn || nn < 0)
    return 0;
  int r = pr[nn] * inv[rr];
  r %= mod;
  r *= inv[nn - rr];
  r %= mod;
  return r;
}

void gya(int ert) {
  pr[0] = 1;
  for (int i = 1; i <= ert; i++) {
    pr[i] = ((ll)pr[i - 1] * i) % mod;
  }
  inv[ert] = beki(pr[ert], mod - 2, mod);
  for (int i = ert - 1; i >= 0; i--) {
    inv[i] = (ll)inv[i + 1] * (i + 1) % mod;
  }
}

//   cin.tie(0);
//	ios::sync_with_stdio(false);
// priority_queue<pa3,vector<pa3>,greater<pa3>> pq;
// sort(ve.begin(),ve.end(),greater<int>());
//   mt19937(clock_per_sec);
//  mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count()) ;

signed main() {
  cin.tie(0);
  ios::sync_with_stdio(false);

  int n, k, c;
  cin >> n >> k >> c;

  string s;
  cin >> s;

  vector<int> ve;
  int mae = -inf;
  int kai = 0;
  for (int i = 0; i < n; i++)
    if (s[i] == 'o') {
      if (i - mae > c) {
        kai++;
        ve.pb(i);
        mae = i;
      }
    }
  if (kai > k)
    return 0;

  reverse(s.begin(), s.end());

  vector<int> ve2;
  mae = -inf;
  // kai=0;
  for (int i = 0; i < n; i++)
    if (s[i] == 'o') {
      if (i - mae > c) {
        kai++;
        ve2.pb(i);
        mae = i;
      }
    }
  reverse(ve2.begin(), ve2.end());
  for (auto &v : ve2)
    v = n - 1 - v;
  for (int i = 0; i < ve.size(); i++) {
    if (ve[i] == ve2[i]) {
      cout << ve[i] + 1 << endl;
    }
  }
  /*
  for(int i=n-1;i>=0;i--){
          if(s[i]=='x')continue;
          int y=ss.segmax(i+1+c,ss.cor).first;
          ve.pb(ss.segmax(i+1+c,ss.cor).second);
          ss.updchan(i,y+1);

  }

  int zen=ss.segmax(0,ss.cor).first;
  ve.pb(ss.segmax(0,ss.cor).second);
  reverse(ve.begin(),ve.end());
  ve.pop_back();

  reverse(ve.begin(),ve.end());


  for(auto v:ve)cout<<v<<" ";
  cout<<endl;



  vector<int> ve2;
  for(int i=n-1;i>=0;i--){
          if(s[i]=='x')continue;
          int y=ss2.segmax(i+1+c,ss2.cor).first;
          ve2.pb(ss2.segmax(i+1+c,ss2.cor).second);
          ss.updchan(i,y+1);

  }

          ve2.pb(ss.segmax(0,ss.cor).second);
  reverse(ve2.begin(),ve2.end());
  ve2.pop_back();

  for(auto &v:ve2)v=n-1-v;

  for(int i=0;i<ve.size();i++){
          if(ve[i]==ve2[i]){
                  cout<<ve[i]+1<<endl;
          }
  }

  */

  return 0;
}


Error: WA

Fixed submission:

#include <bits/stdc++.h>

//    #include <boost/multiprecision/cpp_int.hpp>
#define int long long
#define inf 1000000007
#define pa pair<int, int>
#define ll long long
#define pal pair<double, double>
#define ppap pair<pa, int>
#define PI 3.14159265358979323846
#define paa pair<int, char>
#define mp make_pair
#define pb push_back
#define EPS (1e-8)

int dx[8] = {0, 1, 0, -1, 1, 1, -1, -1};
int dy[8] = {1, 0, -1, 0, -1, 1, 1, -1};
using namespace std;
class pa3 {
public:
  int x;
  int y, z;
  pa3(int x = 0, int y = 0, int z = 0) : x(x), y(y), z(z) {}
  bool operator<(const pa3 &p) const {
    if (x != p.x)
      return x < p.x;
    if (y != p.y)
      return y < p.y;
    return z < p.z;
    // return x != p.x ? x<p.x: y<p.y;
  }
  bool operator>(const pa3 &p) const {
    if (x != p.x)
      return x > p.x;
    if (y != p.y)
      return y > p.y;
    return z > p.z;
    // return x != p.x ? x<p.x: y<p.y;
  }
  bool operator==(const pa3 &p) const {
    return x == p.x && y == p.y && z == p.z;
  }
  bool operator!=(const pa3 &p) const {
    return !(x == p.x && y == p.y && z == p.z);
  }
};

class pa4 {
public:
  int x;
  int y, z, w;
  pa4(int x = 0, int y = 0, int z = 0, int w = 0) : x(x), y(y), z(z), w(w) {}
  bool operator<(const pa4 &p) const {
    if (x != p.x)
      return x < p.x;
    if (y != p.y)
      return y < p.y;
    if (z != p.z)
      return z < p.z;
    return w < p.w;
    // return x != p.x ? x<p.x: y<p.y;
  }
  bool operator>(const pa4 &p) const {
    if (x != p.x)
      return x > p.x;
    if (y != p.y)
      return y > p.y;
    if (z != p.z)
      return z > p.z;
    return w > p.w;
    // return x != p.x ? x<p.x: y<p.y;
  }
  bool operator==(const pa4 &p) const {
    return x == p.x && y == p.y && z == p.z && w == p.w;
  }
};
class pa2 {
public:
  int x, y;
  pa2(int x = 0, int y = 0) : x(x), y(y) {}
  pa2 operator+(pa2 p) { return pa2(x + p.x, y + p.y); }
  pa2 operator-(pa2 p) { return pa2(x - p.x, y - p.y); }
  bool operator<(const pa2 &p) const { return y != p.y ? y < p.y : x < p.x; }
  bool operator>(const pa2 &p) const { return x != p.x ? x < p.x : y < p.y; }
  bool operator==(const pa2 &p) const {
    return abs(x - p.x) == 0 && abs(y - p.y) == 0;
  }
  bool operator!=(const pa2 &p) const {
    return !(abs(x - p.x) == 0 && abs(y - p.y) == 0);
  }
};

string itos(int i) {
  ostringstream s;
  s << i;
  return s.str();
}

int gcd(int v, int b) {
  if (v == 0)
    return b;
  if (b == 0)
    return v;
  if (v > b)
    return gcd(b, v);
  if (v == b)
    return b;
  if (b % v == 0)
    return v;
  return gcd(v, b % v);
}

int mod;
int extgcd(int a, int b, int &x, int &y) {
  if (b == 0) {
    x = 1;
    y = 0;
    return a;
  }
  int d = extgcd(b, a % b, y, x);
  y -= a / b * x;
  return d;
}
pa operator+(const pa &l, const pa &r) {
  return {l.first + r.first, l.second + r.second};
}
pa operator-(const pa &l, const pa &r) {
  return {l.first - r.first, l.second - r.second};
}
int beki(int wa, int rr, int warukazu) {
  if (rr == 0)
    return 1 % warukazu;
  if (rr == 1)
    return wa % warukazu;
  wa %= warukazu;
  if (rr % 2 == 1)
    return ((ll)beki(wa, rr - 1, warukazu) * (ll)wa) % warukazu;
  ll zx = beki(wa, rr / 2, warukazu);
  return (zx * zx) % warukazu;
}

int pr[1000100];
int inv[1000010];

int comb(int nn, int rr) {
  if (rr < 0 || rr > nn || nn < 0)
    return 0;
  int r = pr[nn] * inv[rr];
  r %= mod;
  r *= inv[nn - rr];
  r %= mod;
  return r;
}

void gya(int ert) {
  pr[0] = 1;
  for (int i = 1; i <= ert; i++) {
    pr[i] = ((ll)pr[i - 1] * i) % mod;
  }
  inv[ert] = beki(pr[ert], mod - 2, mod);
  for (int i = ert - 1; i >= 0; i--) {
    inv[i] = (ll)inv[i + 1] * (i + 1) % mod;
  }
}

//   cin.tie(0);
//	ios::sync_with_stdio(false);
// priority_queue<pa3,vector<pa3>,greater<pa3>> pq;
// sort(ve.begin(),ve.end(),greater<int>());
//   mt19937(clock_per_sec);
//  mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count()) ;

struct Segmax {
  //       1
  //   2        3
  // 4   5   6    7

private:
public:
  // (1<<15)=32768
  // 1<<16 = 65536
  // 1<<17 = 131072
  // 1<<18 = 262144

  int cor = (1 << 19);

  vector<pa> vec;

  void shoki1() {

    vec.resize(2 * cor + 3, mp(0, 0));
    for (int i = cor; i < 2 * cor; i++)
      vec[i].second = i - cor;
  }
  void shoki2() {
    for (int i = cor - 1; i > 0; i--) {
      if (vec[2 * i].first >= vec[2 * i + 1].first)
        vec[i] = vec[2 * i];
      else
        vec[i] = vec[2 * i + 1];
    }
  }

  void updadd(int x, int w) {
    // x 項目に w加算
    x += cor;
    vec[x].first += w;
    while (1) {
      x /= 2;
      if (x == 0)
        break;
      if (vec[2 * x].first >= vec[2 * x + 1].first)
        vec[x] = vec[2 * x];
      else
        vec[x] = vec[2 * x + 1];
    }
  }

  void updchan(int x, int w) {
    // x項目をwに変更

    x += cor;
    vec[x].first = w;

    while (1) {
      x /= 2;
      if (x == 0)
        break;
      if (vec[2 * x].first >= vec[2 * x + 1].first)
        vec[x] = vec[2 * x];
      else
        vec[x] = vec[2 * x + 1];
    }
  }
  // [a,b)
  // k-th node
  // k no kukanha [l,r)
  pa segmax(int a, int b, int k = 1, int l = 0, int r = -10) {
    if (r < 0)
      r = cor;

    //	cout<<a<<" "<<b<<" "<<k<<" "<<l<<" "<<r<<endl;

    if (a <= l && r <= b) {
      return vec[k];
    }
    if (r <= a || b <= l) {
      return mp(-(1ll << 31), -1);
    }

    pa v1 = segmax(a, b, k * 2, l, (l + r) / 2),
       v2 = segmax(a, b, k * 2 + 1, (l + r) / 2, r);

    if (v1.first >= v2.first)
      return v1;
    else
      return v2;
  }

  // leftmost
  // ブロックkは値がb以上のときに，このブロックに属する値がb以上のもののうち最も左のものを返す
  pa leftmost(int b, int k, int l, int r) {
    if (r - l == 1)
      return vec[k];
    if (vec[2 * k].first >= b)
      return leftmost(b, 2 * k, l, (l + r) / 2);
    else
      return leftmost(b, 2 * k + 1, (l + r) / 2, r);
  }

  // bound インデックスがa以上で値がb以上の最小のものを返す
  // ないなら(-1,-1)
  pa bound(int a, int b, int k = -1, int l = 0, int r = 0) {
    if (k < 0) {
      k = cor + a;
      l = a, r = a + 1;
    }
    //	cout<<k<<" "<<l<<" "<<r<<endl;
    if (vec[k].first >= b)
      return leftmost(b, k, l, r);
    if (r == cor)
      return mp(-1, -1);
    if (k % 2 == 0) {
      int dd = r - l;
      return bound(a, b, k + 1, r, r + dd);
    } else {
      int dd = r - l;
      return bound(a, b, k / 2 + 1, r, r + 2 * dd);
    }
  }
};

signed main() {
  cin.tie(0);
  ios::sync_with_stdio(false);

  int n, k, c;
  cin >> n >> k >> c;

  string s;
  cin >> s;
  Segmax ss, ss2;

  ss.shoki1();
  ss.shoki2();
  ss2.shoki1();
  ss2.shoki2();

  vector<int> ve;
  int mae = -inf;
  int kai = 0;
  for (int i = 0; i < n; i++)
    if (s[i] == 'o') {
      if (i - mae > c) {
        kai++;
        ve.pb(i);
        mae = i;
      }
    }
  if (kai > k)
    return 0;

  reverse(s.begin(), s.end());

  vector<int> ve2;
  mae = -inf;
  // kai=0;
  for (int i = 0; i < n; i++)
    if (s[i] == 'o') {
      if (i - mae > c) {
        kai++;
        ve2.pb(i);
        mae = i;
      }
    }
  reverse(ve2.begin(), ve2.end());
  for (auto &v : ve2)
    v = n - 1 - v;
  for (int i = 0; i < kai; i++) {
    if (ve[i] == ve2[i]) {
      cout << ve[i] + 1 << endl;
    }
  }
  /*
  for(int i=n-1;i>=0;i--){
          if(s[i]=='x')continue;
          int y=ss.segmax(i+1+c,ss.cor).first;
          ve.pb(ss.segmax(i+1+c,ss.cor).second);
          ss.updchan(i,y+1);

  }

  int zen=ss.segmax(0,ss.cor).first;
  ve.pb(ss.segmax(0,ss.cor).second);
  reverse(ve.begin(),ve.end());
  ve.pop_back();

  reverse(ve.begin(),ve.end());


  for(auto v:ve)cout<<v<<" ";
  cout<<endl;



  vector<int> ve2;
  for(int i=n-1;i>=0;i--){
          if(s[i]=='x')continue;
          int y=ss2.segmax(i+1+c,ss2.cor).first;
          ve2.pb(ss2.segmax(i+1+c,ss2.cor).second);
          ss.updchan(i,y+1);

  }

          ve2.pb(ss.segmax(0,ss.cor).second);
  reverse(ve2.begin(),ve2.end());
  ve2.pop_back();

  for(auto &v:ve2)v=n-1-v;

  for(int i=0;i<ve.size();i++){
          if(ve[i]==ve2[i]){
                  cout<<ve[i]+1<<endl;
          }
  }

  */

  return 0;
}