Problem p02851 (C++)

Buggy submission (status: Runtime Error):
#pragma GCC optimize("O3")
#pragma GCC target("avx")
// #include<bits/stdc++.h>
#include <algorithm>
#include <cstdio>
using namespace std;
typedef long long ll;
#define rep(i, n) for (int i = 0; i < (n); i++)
#define rep1(i, n) for (int i = 1; i <= (n); i++)
#define co(x) cout << (x) << "\n"
#define cosp(x) cout << (x) << " "
#define ce(x) cerr << (x) << "\n"
#define cesp(x) cerr << (x) << " "
#define pb push_back
#define mp make_pair
#define chmin(x, y) x = min(x, y)
#define chmax(x, y) x = max(x, y)
#define Would
#define you
#define please

const int cm = 1 << 17;
char cn[cm], *ci = cn + cm, ct;
inline char getcha() {
  if (ci - cn == cm) {
    fread_unlocked(cn, 1, cm, stdin);
    ci = cn;
  }
  return *ci++;
}
inline int getint() {
  int A = 0;
  if (ci - cn + 16 > cm)
    while ((ct = getcha()) >= '0')
      A = A * 10 + ct - '0';
  else
    while ((ct = *ci++) >= '0')
      A = A * 10 + ct - '0';
  return A;
}

ll tmp[200001];
void pakuri_sort(int N, ll A[]) {
  const int b = 8;
  for (int k = 4; k < 8; k++) {
    int kazu[1 << b] = {}, kazu2[1 << b] = {};
    rep(i, N) kazu[A[i] >> k * b & ((1 << b) - 1)]++;
    rep(i, (1 << b) - 1) kazu[i + 1] += kazu[i];
    for (int i = N - 1; i >= 0; i--)
      tmp[--kazu[A[i] >> k * b & ((1 << b) - 1)]] = A[i];
    k++;
    rep(i, N) kazu2[tmp[i] >> k * b & ((1 << b) - 1)]++;
    rep(i, (1 << b) - 1) kazu2[i + 1] += kazu2[i];
    for (int i = N - 1; i >= 0; i--)
      A[--kazu2[tmp[i] >> k * b & ((1 << b) - 1)]] = tmp[i];
  }
}

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

  const int m = (1 << 20) - 1;
  int N = getint(), K = getint();
  ll A[200001];
  A[0] = 0;
  rep(i, N) {
    ll kari = (A[i] >> 32) + (getint() - 1) % K;
    if (kari >= K)
      kari -= K;
    A[i + 1] = (kari << 32) + i + 1;
  }

  pakuri_sort(N + 1, A);
  int kazu = 0;
  int mae = A[0] >> 32;
  rep(i, N + 1) {
    if (mae != A[i] >> 32) {
      kazu++;
      mae = A[i] >> 32;
    }
    tmp[A[i] & m] = kazu;
  }
  rep(i, N + 1) A[i] = 0;

  ll kotae = 0;
  rep(i, K - 1) {
    kotae += A[tmp[i]];
    A[tmp[i]]++;
  }
  for (int i = K - 1; i <= N; i++) {
    kotae += A[tmp[i]];
    A[tmp[i]]++;
    A[tmp[i - K + 1]]--;
  }

  printf("%lld", kotae);

  Would you please return 0;
}

Fixed submission:
#pragma GCC optimize("O3")
#pragma GCC target("avx")
// #include<bits/stdc++.h>
#include <algorithm>
#include <cstdio>
using namespace std;
typedef long long ll;
#define rep(i, n) for (int i = 0; i < (n); i++)
#define rep1(i, n) for (int i = 1; i <= (n); i++)
#define co(x) cout << (x) << "\n"
#define cosp(x) cout << (x) << " "
#define ce(x) cerr << (x) << "\n"
#define cesp(x) cerr << (x) << " "
#define pb push_back
#define mp make_pair
#define chmin(x, y) x = min(x, y)
#define chmax(x, y) x = max(x, y)
#define Would
#define you
#define please

const int cm = 1 << 17;
char cn[cm], *ci = cn + cm, ct;
inline char getcha() {
  if (ci - cn == cm) {
    fread_unlocked(cn, 1, cm, stdin);
    ci = cn;
  }
  return *ci++;
}
inline int getint() {
  int A = 0;
  if (ci - cn + 16 > cm)
    while ((ct = getcha()) >= '0')
      A = A * 10 + ct - '0';
  else
    while ((ct = *ci++) >= '0')
      A = A * 10 + ct - '0';
  return A;
}

ll tmp[200001];
void pakuri_sort(int N, ll A[]) {
  const int b = 8;
  for (int k = 4; k < 8; k++) {
    int kazu[1 << b] = {}, kazu2[1 << b] = {};
    rep(i, N) kazu[A[i] >> k * b & ((1 << b) - 1)]++;
    rep(i, (1 << b) - 1) kazu[i + 1] += kazu[i];
    for (int i = N - 1; i >= 0; i--)
      tmp[--kazu[A[i] >> k * b & ((1 << b) - 1)]] = A[i];
    k++;
    rep(i, N) kazu2[tmp[i] >> k * b & ((1 << b) - 1)]++;
    rep(i, (1 << b) - 1) kazu2[i + 1] += kazu2[i];
    for (int i = N - 1; i >= 0; i--)
      A[--kazu2[tmp[i] >> k * b & ((1 << b) - 1)]] = tmp[i];
  }
}

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

  const int m = (1 << 20) - 1;
  int N = getint(), K = getint();
  ll A[200001];
  A[0] = 0;
  rep(i, N) {
    ll kari = (A[i] >> 32) + (getint() - 1) % K;
    if (kari >= K)
      kari -= K;
    A[i + 1] = (kari << 32) + i + 1;
  }

  pakuri_sort(N + 1, A);
  int kazu = 0;
  int mae = A[0] >> 32;
  rep(i, N + 1) {
    if (mae != A[i] >> 32) {
      kazu++;
      mae = A[i] >> 32;
    }
    tmp[A[i] & m] = kazu;
  }
  rep(i, N + 1) A[i] = 0;

  ll kotae = 0;
  rep(i, min(N + 1, K - 1)) {
    kotae += A[tmp[i]];
    A[tmp[i]]++;
  }
  for (int i = K - 1; i <= N; i++) {
    kotae += A[tmp[i]];
    A[tmp[i]]++;
    A[tmp[i - K + 1]]--;
  }

  printf("%lld", kotae);

  Would you please return 0;
}