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39 lines
734 B
C++
39 lines
734 B
C++
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#include <iostream>
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using std::cin;
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using std::cout;
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const char endl = '\n';
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const int mod = 998244353;
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int n;
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long long f[1000005][10], ans;
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int main() {
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cin >> n;
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if (n == 1) {
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cout << 9 << endl;
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exit(0);
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}
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for (int i = 1; i <= 9; i++) {
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f[1][i] = 1;
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}
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for (int i = 2; i <= n; i++) {
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for (int j = 1; j <= 9; j++) {
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f[i][j] = f[i - 1][j];
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if (j > 1) {
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f[i][j] += f[i - 1][j - 1];
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}
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if (j < 9) {
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f[i][j] += f[i - 1][j + 1];
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}
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f[i][j] %= mod;
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}
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}
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for (int i = 0; i <= 9; i++) {
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ans += f[n][i];
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}
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cout << ans % mod << endl;
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return 0;
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}
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