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https://git.sb/baoshuo/OI-codes.git
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57 lines
938 B
C++
57 lines
938 B
C++
#include <iostream>
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#include <algorithm>
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#include <cmath>
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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 = 255,
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W = 1005;
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const double eps = 1e-6;
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int n, w, a[N], b[N];
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double f[W];
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bool check(double x) {
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std::fill_n(f + 1, w, -1e9);
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for (int i = 1; i <= n; i++) {
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for (int j = w; j >= 0; j--) {
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int k = std::min(w, j + a[i]);
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f[k] = std::max(f[k], f[j] + b[i] - x * a[i]);
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}
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}
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return f[w] >= 0;
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}
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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 >> n >> w;
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for (int i = 1; i <= n; i++) {
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cin >> a[i] >> b[i];
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}
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double l = 0,
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r = 1e6;
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while (r - l > eps) {
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double mid = (l + r) / 2;
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if (check(mid)) {
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l = mid;
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} else {
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r = mid;
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}
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}
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cout << static_cast<int>(std::floor(l * 1000)) << endl;
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return 0;
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}
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