36 lines
949 B
C++
36 lines
949 B
C++
#include <bits/stdc++.h>
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using namespace std;
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const int mod = 998244353;
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int t, n, a[8005], nxt[8005];
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long long f[8005];
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int main() {
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scanf("%d", &t);
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while (t--) {
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scanf("%d", &n);
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for (int i = 1; i <= n; i++)
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scanf("%d", &a[i]);
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f[0] = 1;
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for (int i = 1; i <= n; i++) {
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int k = i + 1;
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for (int j = 0; j <= i; j++)
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nxt[j] = i + 1;
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for (int j = i - 1; j >= 1; j--) {
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while (k != i + 1 && a[k - 1] != a[j])
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k = nxt[k];
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if (a[k - 1] == a[j])
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k--;
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nxt[j] = k;
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}
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for (int j = i - 1; j >= 0; j--)
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if (nxt[j + 1] == i + 1)
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f[i] = (f[i] + f[j]) % mod;
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}
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printf("%lld\n", f[n]);
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memset(f, 0, sizeof(f[0]) * (n + 1));
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}
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return 0;
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}
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/*
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KMP
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ABA.rev = A.rev + B.rev + A.rev
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*/ |