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46 lines
893 B
C++
46 lines
893 B
C++
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#include <iostream>
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#include <iomanip>
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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 N = 15 + 2,
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K = 105;
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int k, n, p[N], s[N];
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double f[K][1 << N];
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int main() {
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std::ios::sync_with_stdio(false);
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cin.tie(nullptr);
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cin >> k >> n;
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for (int i = 1, x; i <= n; i++) {
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cin >> p[i];
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while (cin >> x, x) {
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s[i] |= 1 << x - 1;
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}
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}
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for (int i = k; i; i--) {
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for (int t = 0; t < 1 << n; t++) {
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for (int j = 1; j <= n; j++) {
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if ((t & s[j]) == s[j]) {
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f[i][t] += std::max(f[i + 1][t], f[i + 1][t | (1 << j - 1)] + p[j]);
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} else {
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f[i][t] += f[i + 1][t];
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}
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}
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f[i][t] /= n;
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}
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}
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cout << std::fixed << std::setprecision(6) << f[1][0] << endl;
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return 0;
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}
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