verify/string/suffix-array/number_of_substrings.test.cpp

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• Last update: 2025-07-19 14:00:36+09:00
• Problem: https://judge.yosupo.jp/problem/number_of_substrings

Depends on

• src/contest/template.hpp
• src/string/suffix-array.hpp

Code

#define PROBLEM "https://judge.yosupo.jp/problem/number_of_substrings"
#include "src/contest/template.hpp"
#include "src/string/suffix-array.hpp"

int main(){
    string s;
    cin >> s;
    SuffixArray sa(s);
    int n=(int)s.size();
    cout << 1LL*n*(n+1)/2-accumulate(sa.lcp.begin(),sa.lcp.end(),0LL);
}

#line 1 "verify/string/suffix-array/number_of_substrings.test.cpp"
#define PROBLEM "https://judge.yosupo.jp/problem/number_of_substrings"
#line 2 "src/contest/template.hpp"
#include<bits/stdc++.h>
#include<ext/pb_ds/assoc_container.hpp>
#include<ext/pb_ds/tree_policy.hpp>
 
using namespace std;
using namespace __gnu_pbds;
 
using ll = long long;
using db = long double;
using vi = vector<int>;
using vl = vector<ll>;
using vd = vector<db>;
using pii = pair<int,int>;
using pll = pair<ll,ll>;
using pdd = pair<db,db>;
const int INF=0x3fffffff;
const ll LINF=0x1fffffffffffffff;
const db DINF=numeric_limits<db>::infinity();
const db EPS=1e-9;
const db PI=acos(db(-1));
 
template<class T>
using ordered_set = tree<T,null_type,less<T>,rb_tree_tag,tree_order_statistics_node_update>;
 
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
mt19937_64 rng64(chrono::steady_clock::now().time_since_epoch().count());
#line 2 "src/string/suffix-array.hpp"

/**
 * Author: Teetat T.
 * Date: 2024-06-14
 * Description: Suffix Array.
 */

template<class STR>
struct SuffixArray{
    int n;
    vector<int> sa,isa,lcp;
    // SparseTable<MinMonoid<int>> st;
    SuffixArray(){}
    SuffixArray(const STR &s){init(s);}
    void init(const STR &s){
        n=(int)s.size();
        sa=isa=lcp=vector<int>(n+1);
        sa[0]=n;
        iota(sa.begin()+1,sa.end(),0);
        sort(sa.begin()+1,sa.end(),[&](int i,int j){return s[i]<s[j];});
        for(int i=1;i<=n;i++){
            int x=sa[i-1],y=sa[i];
            isa[y]=i>1&&s[x]==s[y]?isa[x]:i;
        }
        for(int len=1;len<=n;len<<=1){
            vector<int> ps(sa),pi(isa),pos(n+1);
            iota(pos.begin(),pos.end(),0);
            for(auto i:ps)if((i-=len)>=0)sa[pos[isa[i]]++]=i;
            for(int i=1;i<=n;i++){
                int x=sa[i-1],y=sa[i];
                isa[y]=pi[x]==pi[y]&&pi[x+len]==pi[y+len]?isa[x]:i;
            }
        }
        for(int i=0,k=0;i<n;i++){
            for(int j=sa[isa[i]-1];j+k<n&&s[j+k]==s[i+k];k++);
            lcp[isa[i]]=k;
            if(k)k--;
        }
        // st.init(lcp);
    }
    // int get_lcp(int i,int j){
    //     if(i==j)return n-i;
    //     auto [l,r]=minmax(isa[i],isa[j]);
    //     return st.query(l+1,r);
    // }
};

#line 4 "verify/string/suffix-array/number_of_substrings.test.cpp"

int main(){
    string s;
    cin >> s;
    SuffixArray sa(s);
    int n=(int)s.size();
    cout << 1LL*n*(n+1)/2-accumulate(sa.lcp.begin(),sa.lcp.end(),0LL);
}

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