24 lines
762 B
C++
24 lines
762 B
C++
struct slice_hash {
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using hash_type = pair<MLL<MDL1>, MLL<MDL2>>;
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int n;
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vector<MLL<MDL1>> pw1;
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vector<MLL<MDL2>> pw2;
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vector<MLL<MDL1>> hash1;
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vector<MLL<MDL2>> hash2;
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slice_hash(const string& s) : n(s.size()), pw1(n + 1), pw2(n + 1), hash1(n + 1), hash2(n + 1) {
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constexpr int b = 31;
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pw1[0] = 1, pw2[0] = 1;
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for (int i = 1; i <= n; ++i) {
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hash1[i] = hash1[i - 1] + s[i - 1] * pw1[i - 1];
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hash2[i] = hash2[i - 1] + s[i - 1] * pw2[i - 1];
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pw1[i] = pw1[i - 1] * b;
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pw2[i] = pw2[i - 1] * b;
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}
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}
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// query [l, r]
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hash_type hash(int l, int r) {
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return { (hash1[r + 1] - hash1[l]) / pw1[l], (hash2[r + 1] - hash2[l]) / pw2[l] };
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}
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};
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