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#pragma GCC optimize("O3","unroll-loops")
#pragma GCC target("avx2,bmi,bmi2,popcnt,lzcnt")

#include <bits/stdc++.h>
using namespace std;

#define int long long
#define rep(i, a, b) for(int i = a; i < (b); ++i)
#define all(x) begin(x), end(x)
#define sz(x) (int)(x).size()
typedef long long ll;
typedef pair<int, int> pii;
typedef vector<int> vi;

string to_string(string s) {
    return '"' + s + '"';
}
 
string to_string(const char* s) {
    return to_string((string) s);
}
 
string to_string(bool b) {
    return (b ? "true" : "false");
}
 
template <typename A, typename B>
string to_string(pair<A, B> p) {
    return "(" + to_string(p.first) + ", " + to_string(p.second) + ")";
}
 
template <typename A>
string to_string(A v) {
    bool first = true;
    string res = "{";
    for (const auto &x : v) {
        if (!first) {
            res += ", ";
        }
        first = false;
        res += to_string(x);
    }
    res += "}";
    return res;
}
 
void debug_out() {
    cerr << endl;
}
 
template <typename Head, typename... Tail>
void debug_out(Head H, Tail... T) {
    cerr << " " << to_string(H);
    debug_out(T...);
}
 
#ifdef LOCAL
#define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)
#else
#define debug(...) 42
#endif

/**
 * Author: chilli
 * License: CC0
 * Description: z[i] computes the length of the longest common prefix of s[i:] and s,
 * except z[0] = 0. (abacaba -> 0010301)
 * Time: O(n)
 * Status: stress-tested
 */

vi Z(const string& S) {
    vi z(sz(S));
    int l = -1, r = -1;
    rep(i,1,sz(S)) {
        z[i] = i >= r ? 0 : min(r - i, z[i - l]);
        while (i + z[i] < sz(S) && S[i + z[i]] == S[z[i]])
            z[i]++;
        if (i + z[i] > r)
            l = i, r = i + z[i];
    }
    return z;
}

void solve() {
    string a, b;
    cin >> a >> b;

    string s = a + '#' + b;
    vi z = Z(s);
    vi ans;
    for (int i = sz(a) + 1; i < sz(z); i++) {
        if (z[i] == sz(a)) {
            ans.push_back(i - sz(a));
        }
    }
    cout << sz(ans) << '\n';
    for (int i : ans) cout << i << ' ';
}

signed main() {
    cin.tie(0)->sync_with_stdio(0);
    cin.exceptions(cin.failbit); // RTE if input wrong datatype

    solve();
}

Test 1

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Test 2

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Test 3

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Test 4

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Test 5

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Test 21

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Test 22

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Test 30

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Test 40

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Test 48

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Test 50

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Test 62

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Test 66

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Test 70

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Test 72

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Test 75

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Test 88

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Test 89

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Test 90

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Test 91

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Test 92

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Test 93

Verdict: ACCEPTED