tests/Number_of_Substrings.test.cpp

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Last update: 2025-11-28 02:09:51+07:00
Problem: https://judge.yosupo.jp/problem/number_of_substrings

Depends on

Code

#define PROBLEM "https://judge.yosupo.jp/problem/number_of_substrings"

#include "../misc/macros.h"
#include "../strings/SuffixArray.h"

void solve() {
  string s;
  cin >> s;
  i64 n = sz(s);
  auto sa = SuffixArray(s);
  i64 ans = n * (n + 1) / 2;
  cout << ans - accumulate(all(sa.lcp), 0ll);
}

int main() {
  solve();
}

#line 1 "tests/Number_of_Substrings.test.cpp"
#define PROBLEM "https://judge.yosupo.jp/problem/number_of_substrings"

#line 1 "misc/macros.h"
// #pragma GCC optimize("Ofast,unroll-loops")       // unroll long, simple loops
// #pragma GCC target("avx2,fma")                   // vectorizing code
// #pragma GCC target("lzcnt,popcnt,abm,bmi,bmi2")  // for fast bitset operation

#include <bits/extc++.h>
#include <tr2/dynamic_bitset>

using namespace std;
using namespace __gnu_pbds;  // ordered_set, gp_hash_table
// using namespace __gnu_cxx; // rope

// for templates to work
#define all(x) (x).begin(), (x).end()
#define sz(x) (int) (x).size()
#define pb push_back
#define eb emplace_back
using i32 = int32_t;
using u32 = uint32_t;
using i64 = int64_t;
using u64 = uint64_t;
using i128 = __int128_t;
using u128 = __uint128_t;
using ld = long double;
using pii = pair<i32, i32>;
using vi = vector<i32>;

// fast map
const int RANDOM = chrono::high_resolution_clock::now().time_since_epoch().count();
struct chash {  // customize hash function for gp_hash_table
  int operator()(int x) const { return x ^ RANDOM; }
};
gp_hash_table<int, int, chash> table;

/* ordered set
    find_by_order(k): returns an iterator to the k-th element (0-based)
    order_of_key(k): returns the number of elements in the set that are strictly less than k
*/
template <class T>
using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

/*  rope
    rope <int> cur = v.substr(l, r - l + 1);
    v.erase(l, r - l + 1);
    v.insert(v.mutable_begin(), cur);
*/
#line 1 "strings/SuffixArray.h"
struct SuffixArray {
  vector<int> sa, lcp, rank;
  SuffixArray(string s, int lim = 256) {
    int n = s.size() + 1, k = 0, a, b;
    s.push_back(0);
    vector<int> y(n), cnt(max(n, lim));
    sa.resize(n), lcp.resize(n), rank.resize(n);
    for (int i = 0; i < n; ++i) rank[i] = s[i];
    iota(sa.begin(), sa.end(), 0);
    
    for (int j = 0, p = 0; p < n; j = max(1, j * 2), lim = p) {
      p = j;
      iota(all(y), n - j);
      for (int i = 0; i < n; ++i)
        if (sa[i] >= j) y[p++] = sa[i] - j;
      fill(all(cnt), 0);
      for (int i = 0; i < n; ++i) cnt[rank[i]]++;
      for (int i = 1; i < lim; ++i) cnt[i] += cnt[i - 1];
      for (int i = n; i--;) sa[--cnt[rank[y[i]]]] = y[i];
      swap(rank, y), p = 1, rank[sa[0]] = 0;
      for (int i = 1; i < n; ++i) {
        a = sa[i - 1], b = sa[i];
        int val_a = (a + j < n) ? y[a + j] : -1;
        int val_b = (b + j < n) ? y[b + j] : -1;
        rank[b] = (y[a] == y[b] && val_a == val_b) ? p - 1 : p++;
      }
    }
    
    for (int i = 0; i < n; ++i) rank[sa[i]] = i;
    for (int i = 0, j; i < n - 1; lcp[rank[i++]] = k)
      for (k && k--, j = sa[rank[i] - 1]; s[i + k] == s[j + k]; k++);
  }
};
#line 5 "tests/Number_of_Substrings.test.cpp"

void solve() {
  string s;
  cin >> s;
  i64 n = sz(s);
  auto sa = SuffixArray(s);
  i64 ans = n * (n + 1) / 2;
  cout << ans - accumulate(all(sa.lcp), 0ll);
}

int main() {
  solve();
}