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struct SuffixArray {
int n, step, count;
vector<int> SA, LCP;
vector<vector<int>> P;
vector<pair<pair<int, int>, int>> L;
SuffixArray(const string& s) : n(sz(s)), SA(n), LCP(n), L(n) {
P.assign(__lg(n)*4-2, vector<int>(n));
for (int i = 0; i < n; i++) P[0][i] = s[i];
for (step = 1, count = 1; count < n; step++, count *= 2) {
for (int i = 0; i < n; i++)
L[i] = {{P[step-1][i],
i+count < n ? P[step-1][i+count] : -1}, i};
sort(all(L));
for (int i = 0; i < n; i++) {
P[step][L[i].second] =
i > 0 && L[i].first == L[i-1].first ?
P[step][L[i-1].second] : i;
}}
for (int i = 0; i < n; i++) SA[i] = L[i].second;
for (int i = 1; i < n; i++) LCP[i] = lcp(SA[i - 1], SA[i]);
}
// x and y are text-indices, not SA-indices.
int lcp(int x, int y) {
int ret = 0;
if (x == y) return n - x;
for (int k = step - 1; k >= 0 && x < n && y < n; k--) {
if (P[k][x] == P[k][y]) {
x += 1 << k;
y += 1 << k;
ret += 1 << k;
}}
return ret;
}
};
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