This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include<bits/stdc++.h>
#define f first
#define s second
#define int long long
using namespace std;
const int N = 2005;
int A = 37;
int B = 1e9 + 9;
int C = 31;
int D = 1e9 + 2;
string s , t;
int pw1[27] , pw2[27];
struct Hash{
    size_t operator() (const pair<int , int> &x) const{
        return ((long long)x.first) ^ (((long long)x.second) << 32);
    }
};
unordered_map<pair<int , int>, int , Hash> H;
main (){
    ios_base::sync_with_stdio(0); cin.tie(0);
    cin >> s >> t;
    int n = s.size() , m = t.size();
    pw1[0] = pw2[0] = 1;
    for(int i = 1; i < 26; ++i) pw1[i] = pw1[i - 1] * A*(i + 1) % B;
    for(int i = 1; i< 26; ++i) pw2[i] = pw2[i - 1] * C*(i + 1) % D;
    for(int i = 0; i < n; ++i){
        int x= 0 , y =0;
        for(int j = i; j < n; ++j){
            x += pw1[s[j] - 'a'];
            y += pw2[s[j] - 'a'];
            if(x>=B)x-=B;
            if(y>=D)y-=D;
           // a[j - i + 1].emplace_back(x , y);
           H[{x, y}]= 1;
        }
    }
    int ans = 0;
    for(int i = 0; i < m; ++i){
        int x= 0 , y =0;
        for(int j = i; j < m; ++j){
            x += pw1[t[j] - 'a'];
            y += pw2[t[j] - 'a'];
            if(x>=B)x-=B;
            if(y>=D)y-=D;
            if(H[{x , y}])ans = max(ans , j - i + 1);
        }
    }
    cout << ans;
}
Compilation message (stderr)
interval.cpp:19:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   19 | main (){
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