CUBE-191: Anagram

#include <bits/stdc++.h>

using namespace std;
using lli = long long;
const int N = 2e3 + 10;
const lli PB = 98765431;
const int AZ = 26 + 10;
char A[N], B[N];
lli cons[AZ];
int la, lb;

int alph(int ch){
    return ch - 'A' + 1;
    /// A, ..., Z = 1, ..., 26
}

bool check(int len){
    unordered_set <lli> HSHA;
    lli hshA = 0;
    for(int i=0;i<len-1;i++)
        hshA += cons[alph(A[i])];

    for(int i=len-1;i<la;i++){
        hshA += cons[alph(A[i])];
        HSHA.insert(hshA);
        hshA -= cons[alph(A[i-len+1])];
    }

    lli hshB = 0;
    for(int i=0;i<len-1;i++)
        hshB += cons[alph(B[i])];

    for(int i=len-1;i<lb;i++){
        hshB += cons[alph(B[i])];
        if(HSHA.find(hshB) != HSHA.end()) return true;
        hshB -= cons[alph(B[i-len+1])];
    }
    return false;
}

int main(){

    scanf("%s%s", &A, &B);

    la = strlen(A);
    lb = strlen(B);

    cons[0] = 1;
    for(int i=1;i<=AZ-10;i++){
        cons[i] = (lli) cons[i-1] * PB;
    }

    for(int len=min(la, lb);len>=0;len--){
        if(check(len)){
            printf("%d", len);
            return 0;
        }
    }

    return 0;
}

/*
ABCDE
DBAEC
L = 3, 4 หาค่าไม่ได้
L = 5    หาค่าได้
*/